2020-05-18 16:49:00

36 files changed, 630 insertions, 408 deletions

diff --git a/tex/context/base/mkii/cont-new.mkii b/tex/context/base/mkii/cont-new.mkii
index 2460e83ce..083a54921 100644
--- a/tex/context/base/mkii/cont-new.mkii
+++ b/tex/context/base/mkii/cont-new.mkii
@@ -11,7 +11,7 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-\newcontextversion{2020.05.12 16:17}
+\newcontextversion{2020.05.18 16:46}
 
 %D This file is loaded at runtime, thereby providing an
 %D excellent place for hacks, patches, extensions and new
diff --git a/tex/context/base/mkii/context.mkii b/tex/context/base/mkii/context.mkii
index 41553e217..2fa248da0 100644
--- a/tex/context/base/mkii/context.mkii
+++ b/tex/context/base/mkii/context.mkii
@@ -20,7 +20,7 @@
 %D your styles an modules.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2020.05.12 16:17}
+\edef\contextversion{2020.05.18 16:46}
 
 %D For those who want to use this:
 
diff --git a/tex/context/base/mkiv/back-pdf.mkiv b/tex/context/base/mkiv/back-pdf.mkiv
index 697aa311f..b8c3d429b 100644
--- a/tex/context/base/mkiv/back-pdf.mkiv
+++ b/tex/context/base/mkiv/back-pdf.mkiv
@@ -88,7 +88,7 @@
 
 \appendtoks
     \edef\p_file{\backendparameter{xmpfile}}%
-    \ifx\p_file\empty\else
+    \ifempty\p_file\else
       \clf_setxmpfile{\p_file}%
     \fi
 \to \everysetupbackend
diff --git a/tex/context/base/mkiv/buff-ver.mkxl b/tex/context/base/mkiv/buff-ver.mkxl
index dec4dfb4a..058681a85 100644
--- a/tex/context/base/mkiv/buff-ver.mkxl
+++ b/tex/context/base/mkiv/buff-ver.mkxl
@@ -78,7 +78,7 @@
    \edef\p_buff_option{\typeparameter\c!option}%
    \ifx\p_buff_option\v!none
      \usetypestyleandcolor\c!style\c!color
-   \orelse\ifx\p_buff_option\empty
+   \orelse\ifempty\p_buff_option
      \usetypestyleandcolor\c!style\c!color
    \else
      \usetypestyleparameter\c!style % no color
@@ -120,7 +120,7 @@
    \edef\p_buff_option{\typingparameter\c!option}%
    \ifx\p_buff_option\v!none
      \usetypingstyleandcolor\c!style\c!color
-   \orelse\ifx\p_buff_option\empty
+   \orelse\ifempty\p_buff_option
      \usetypingstyleandcolor\c!style\c!color
    \else
      \usetypingstyleparameter\c!style % no color !
@@ -177,7 +177,7 @@
 \appendtoks
     \setuevalue{\e!start\currenttyping}{\buff_verbatim_typing_start{\currenttyping}}%
     \setuevalue{\e!stop \currenttyping}{\buff_verbatim_typing_stop {\currenttyping}}%
-    \ifx\currenttypingparent\empty
+    \ifempty\currenttypingparent
       \normalexpanded{\definelinenumbering[\currenttyping]}%
     \else
       \normalexpanded{\definelinenumbering[\currenttyping][\currenttypingparent]}%
@@ -610,10 +610,10 @@
 
 \unexpanded\def\doifelsetypingfile#1%
   {\edef\askedtypingfile{\locfilename{#1}}%
-   \ifx\askedtypingfile\empty
+   \ifempty\askedtypingfile
      \edef\askedtypingfile{\locfilename{#1.tex}}% downward compatible
    \fi
-   \ifx\askedtypingfile\empty
+   \ifempty\askedtypingfile
      \expandafter\secondoftwoarguments
    \else
      \expandafter\firstoftwoarguments
diff --git a/tex/context/base/mkiv/colo-ini.mkxl b/tex/context/base/mkiv/colo-ini.mkxl
index ee2dc64a6..d2c3e610d 100644
--- a/tex/context/base/mkiv/colo-ini.mkxl
+++ b/tex/context/base/mkiv/colo-ini.mkxl
@@ -167,7 +167,7 @@
 \unexpanded\def\coloronly[#1]%
   {\bgroup
    \edef\currentcolorname{#1}%
-   \ifx\currentcolorprefix\empty
+   \ifempty\currentcolorprefix
      \colo_helpers_activate_nop_only
    \else
      \colo_helpers_activate_yes_only
@@ -177,7 +177,7 @@
 \unexpanded\def\startcoloronly[#1]%$
   {\begingroup
    \edef\currentcolorname{#1}%
-   \ifx\currentcolorprefix\empty
+   \ifempty\currentcolorprefix
      \colo_helpers_activate_nop_only
    \else
      \colo_helpers_activate_yes_only
@@ -191,7 +191,7 @@
 \unexpanded\def\color[#1]%
   {\bgroup
    \edef\currentcolorname{#1}%
-   \ifx\currentcolorprefix\empty
+   \ifempty\currentcolorprefix
      \colo_helpers_activate_nop
    \else
      \colo_helpers_activate_yes
@@ -206,7 +206,7 @@
 \unexpanded\def\startcolor[#1]%$
   {\begingroup
    \edef\currentcolorname{#1}%
-   \ifx\currentcolorprefix\empty
+   \ifempty\currentcolorprefix
      \colo_helpers_activate_nop
    \else
      \colo_helpers_activate_yes
@@ -232,7 +232,7 @@
 \unexpanded\def\fastcolor[#1]#2%
   {\begingroup % is this command still needed?
    \edef\currentcolorname{#1}%
-   \ifx\currentcolorprefix\empty
+   \ifempty\currentcolorprefix
      \colo_helpers_activate_nop
    \else
      \colo_helpers_activate_yes
@@ -242,7 +242,7 @@
 
 \unexpanded\def\directcolor[#1]%
   {\edef\currentcolorname{#1}%
-   \ifx\currentcolorprefix\empty
+   \ifempty\currentcolorprefix
      \colo_helpers_activate_nop
    \else
      \colo_helpers_activate_yes
@@ -250,7 +250,7 @@
 
 %D The following command is obsolete:
 
-\unexpanded\def\startcolorpage   {\startcolor[\ifx\maintextcolor\empty\defaulttextcolor\else\maintextcolor\fi]}
+\unexpanded\def\startcolorpage   {\startcolor[\ifempty\maintextcolor\defaulttextcolor\else\maintextcolor\fi]}
 \unexpanded\def\stopcolorpage    {\stopcolor}
 
 \unexpanded\def\getcolorattributevalue#1#2% obsolete, use \thecolorattribute instead ...
@@ -546,7 +546,7 @@
 
 \def\colo_palets_setup[#1]%
   {\edef\currentcolorpalet{#1}%
-   \ifx\currentcolorpalet\empty
+   \ifempty\currentcolorpalet
      % seems to be a reset
      \let\currentcolorprefix\empty
     %\t_colo_prefix\emptytoks
@@ -728,7 +728,7 @@
 % new: expandable (see tbl)
 
 \def\colo_helpers_fast_activate
-  {\ifx\currentcolorprefix\empty
+  {\ifempty\currentcolorprefix
      \expandafter\colo_helpers_fast_activate_nop
    \else
      \expandafter\colo_helpers_fast_activate_yes
@@ -759,7 +759,7 @@
 
 \def\colo_helpers_activate#1% two-step is not that much faster but less tracing
   {\edef\currentcolorname{#1}%
-   \ifx\currentcolorprefix\empty
+   \ifempty\currentcolorprefix
     %\expandafter
      \colo_helpers_activate_nop
    \else
@@ -1097,10 +1097,10 @@
 \def\s!themaintextcolor{themaintextcolor}
 
 \unexpanded\def\inheritmaintextcolor
-  {\ifx\maintextcolor\empty\else\colo_helpers_activate\maintextcolor\fi}
+  {\ifempty\maintextcolor\else\colo_helpers_activate\maintextcolor\fi}
 
 \unexpanded\def\onlyinheritmaintextcolor
-  {\ifx\maintextcolor\empty
+  {\ifempty\maintextcolor
      \deactivatecolor
    \else
      \colo_helpers_activate\maintextcolor
@@ -1127,7 +1127,7 @@
 
 \def\colo_helpers_initialize_maintextcolor
   {\edef\p_colo_textcolor{\directcolorsparameter\c!textcolor}%
-   \ifx\p_colo_textcolor\empty
+   \ifempty\p_colo_textcolor
      \colo_helpers_switch_to_maintextcolor\defaulttextcolor
    \else
      \colo_helpers_switch_to_maintextcolor\p_colo_textcolor
diff --git a/tex/context/base/mkiv/cont-new.mkiv b/tex/context/base/mkiv/cont-new.mkiv
index 93fc7b12c..1857b934a 100644
--- a/tex/context/base/mkiv/cont-new.mkiv
+++ b/tex/context/base/mkiv/cont-new.mkiv
@@ -13,7 +13,7 @@
 
 % \normalend % uncomment this to get the real base runtime
 
-\newcontextversion{2020.05.12 16:17}
+\newcontextversion{2020.05.18 16:46}
 
 %D This file is loaded at runtime, thereby providing an excellent place for
 %D hacks, patches, extensions and new features.
diff --git a/tex/context/base/mkiv/context.mkiv b/tex/context/base/mkiv/context.mkiv
index 7adad8602..de600c70b 100644
--- a/tex/context/base/mkiv/context.mkiv
+++ b/tex/context/base/mkiv/context.mkiv
@@ -45,7 +45,7 @@
 %D {YYYY.MM.DD HH:MM} format.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2020.05.12 16:17}
+\edef\contextversion{2020.05.18 16:46}
 \edef\contextkind   {beta}
 
 %D Kind of special:
diff --git a/tex/context/base/mkiv/context.mkxl b/tex/context/base/mkiv/context.mkxl
index 1e4d4b45c..8054489ff 100644
--- a/tex/context/base/mkiv/context.mkxl
+++ b/tex/context/base/mkiv/context.mkxl
@@ -29,7 +29,7 @@
 %D {YYYY.MM.DD HH:MM} format.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2020.05.12 16:17}
+\edef\contextversion{2020.05.18 16:46}
 \edef\contextkind   {beta}
 
 %D Kind of special:
diff --git a/tex/context/base/mkiv/font-emp.mklx b/tex/context/base/mkiv/font-emp.mklx
index 2bd6f3cf9..8ceee2723 100644
--- a/tex/context/base/mkiv/font-emp.mklx
+++ b/tex/context/base/mkiv/font-emp.mklx
@@ -46,7 +46,7 @@
      #slanted%
    \orelse\ifx\m_font_emphasized_typeface\v!italic
      #italic%
-   \orelse\ifx\m_font_emphasized_typeface\empty
+   \orelse\ifempty\m_font_emphasized_typeface
      #slanted%
    \else
      \csname\m_font_emphasized_typeface\endcsname
diff --git a/tex/context/base/mkiv/font-fil.mklx b/tex/context/base/mkiv/font-fil.mklx
index 6cc25db10..2b8224dfe 100644
--- a/tex/context/base/mkiv/font-fil.mklx
+++ b/tex/context/base/mkiv/font-fil.mklx
@@ -78,7 +78,7 @@
 \unexpanded\def\definefontsynonym[#name]#crap[#file]%
   {\edef\m_font_name{#name}%
    \edef\m_font_file{#file}%
-   \ifx\fontclass\empty
+   \ifempty\fontclass
       \expandafter\font_basics_define_font_synonym_nop
    \else
       \expandafter\font_basics_define_font_synonym_yes
@@ -95,7 +95,7 @@
 \unexpanded\def\edefinefontsynonym[#name]#crap[#file]%
   {\edef\m_font_name{#name}%
    \edef\m_font_file{#file}%
-   \ifx\fontclass\empty
+   \ifempty\fontclass
       \expandafter\font_basics_define_font_synonym_nop_expanded
    \else
       \expandafter\font_basics_define_font_synonym_yes_expanded
@@ -207,7 +207,7 @@
 
 \def\font_helpers_true_fontname#name*#first#rest*#crap\relax
   {\ifcsname\??fontfile\fontclass#name\endcsname
-     \ifx#first\empty
+     \ifempty#first%
       %\expandafter\truefontname\csname\??fontfile\fontclass#name\endcsname
        \expandafter\truefontname\lastnamedcs
      \else
@@ -215,7 +215,7 @@
        \expandafter\font_helpers_true_fontname_check\lastnamedcs*#first#rest%
      \fi
    \orelse\ifcsname\??fontfile\defaultfontclass#name\endcsname
-     \ifx#first\empty
+     \ifempty#first%
       %\expandafter\truefontname\csname\??fontfile\defaultfontclass#name\endcsname
        \expandafter\truefontname\lastnamedcs
      \else
@@ -223,7 +223,7 @@
        \expandafter\font_helpers_true_fontname_check\lastnamedcs*#first#rest%
      \fi
    \orelse\ifcsname\??fontfile#name\endcsname
-     \ifx#first\empty
+     \ifempty#first%
       %\expandafter\truefontname\csname\??fontfile#name\endcsname
        \expandafter\truefontname\lastnamedcs
      \else
@@ -231,7 +231,7 @@
        \expandafter\font_helpers_true_fontname_check\lastnamedcs*#first#rest%
      \fi
    \else
-     #name\ifx#first\empty\else*#first#rest\fi
+     #name\ifempty#first\else*#first#rest\fi
    \fi}
 
 \def\font_helpers_true_fontname_check#name%
@@ -401,7 +401,7 @@
    \font_helpers_set_designsize_nop\somefontname}
 
 \def\font_helpers_update_font_parameters
- {\ifx\fontclass\empty\font_helpers_update_font_parameters_nop\else\font_helpers_update_font_parameters_yes\fi}
+ {\ifempty\fontclass\font_helpers_update_font_parameters_nop\else\font_helpers_update_font_parameters_yes\fi}
 
 \installcorenamespace{fontclass}
 
diff --git a/tex/context/base/mkiv/font-ini.mklx b/tex/context/base/mkiv/font-ini.mklx
index 4b112322d..db031ba42 100644
--- a/tex/context/base/mkiv/font-ini.mklx
+++ b/tex/context/base/mkiv/font-ini.mklx
@@ -756,7 +756,7 @@
    \font_helpers_update_font_class_parameters
   %\writestatus{fonts}{low level define: #csname/\somefontfile/\number\d_font_scaled_font_size/\fontface/\number\d_font_scaled_text_face}%
    \clf_definefont_two
-      \ifx\fontclass\empty\s!false\else\s!true\fi
+      \ifempty\fontclass\s!false\else\s!true\fi
       {#csname}%
       {\somefontfile}%
       \d_font_scaled_font_size
@@ -1440,7 +1440,7 @@
    \processcommalist[#assignments]\font_basics_define_body_font_defs}
 
 \unexpanded\def\font_basics_define_body_font_defs
-  {\ifx\fontclass\empty
+  {\ifempty\fontclass
      \expandafter\font_basics_define_body_font_defs_nop
    \else
      \expandafter\font_basics_define_body_font_defs_yes
@@ -1670,7 +1670,7 @@
 
 \def\font_helpers_set_font#method#specification%
   {\edef\m_font_specification{#specification}%
-   \ifx\m_font_specification\empty \else
+   \ifempty\m_font_specification \else
      \ifx\m_font_specification\v!global % we can have all kind of presets
        \restoreglobalbodyfont
      \else
@@ -1680,7 +1680,7 @@
          \font_preloads_at_definition
          \font_basics_switch_points\normalizedbodyfontsize
          \font_basics_switch_style\fontstyle
-         \ifx\defaultfontclass\empty
+         \ifempty\defaultfontclass
            \let\defaultfontclass\fontclass
          \fi
        \fi
@@ -1829,7 +1829,7 @@
    \font_helpers_synchronize_font}
 
 \unexpanded\def\font_helpers_synchronize_font % we can have dups i.e. no need to let fontstrategy
-  {\ifx\fontclass\empty
+  {\ifempty\fontclass
      \applyfontstrategies
    \else
      \applyfontclassstrategies
@@ -2227,7 +2227,7 @@
 
 \unexpanded\def\font_basics_switchtobodyfont#specification%
   {\edef\m_font_step{\font_bodyfontvariable{#specification}}%
-   \ifx\m_font_step\empty
+   \ifempty\m_font_step
      \font_helpers_set_font\zerocount{#specification}%
    \else
      \font_helpers_switch_bodyfont_step % so we have a fast [small] switch
@@ -2240,7 +2240,7 @@
 
 \unexpanded\def\usebodyfontparameter#1%
   {\edef\m_font_bodyfont_asked{#1\c!bodyfont}%
-   \ifx\m_font_bodyfont_asked\empty\else
+   \ifempty\m_font_bodyfont_asked\else
      \font_basics_switchtobodyfont\m_font_bodyfont_asked
    \fi}
 
@@ -2285,7 +2285,7 @@
 %D \stoptyping
 
 \unexpanded\def\usebodyfont[#1]%
-  {\ifx\fontclass\empty
+  {\ifempty\fontclass
      \setupbodyfont[#1]%
    \else
      \switchtobodyfont[#1]%
diff --git a/tex/context/base/mkiv/font-sty.mklx b/tex/context/base/mkiv/font-sty.mklx
index 81884333b..f0fe65183 100644
--- a/tex/context/base/mkiv/font-sty.mklx
+++ b/tex/context/base/mkiv/font-sty.mklx
@@ -148,7 +148,7 @@
 
 \unexpanded\def\doconvertfont#specification% takes second argument / this command is obsolete
   {\edef\m_current_convert_font{#specification}%
-   \ifx\m_current_convert_font\empty
+   \ifempty\m_current_convert_font
     %\expandafter\firstofoneargument
    \else
      \expandafter\font_helpers_do_convert_font
@@ -183,7 +183,7 @@
 
 \unexpanded\def\dousestyleparameter#value%
   {\edef\currentstyleparameter{#value}%
-   \ifx\currentstyleparameter\empty\else
+   \ifempty\currentstyleparameter\else
      \expandafter\dousecurrentstyleparameter
    \fi}
 
diff --git a/tex/context/base/mkiv/lang-ini.mkxl b/tex/context/base/mkiv/lang-ini.mkxl
index 8bcba01d8..f86628069 100644
--- a/tex/context/base/mkiv/lang-ini.mkxl
+++ b/tex/context/base/mkiv/lang-ini.mkxl
@@ -121,7 +121,7 @@
 
 \unexpanded\def\setusedlanguage#1%
   {\edef\currentusedlanguage{\reallanguagetag{#1}}%
-   \ifx\currentusedlanguage\empty
+   \ifempty\currentusedlanguage
      \let\currentusedlanguage  \currentlanguage
      \let\usedlanguageparameter\languageparameter
    \orelse\ifx\currentusedlanguage\v!global
@@ -139,14 +139,14 @@
 
 \unexpanded\def\setcurrentlanguage#1#2% sets modes: **id (currentmain) *id (current)
   {\edef\xaskedlanguage{#1}% otherwise clash with \askedlanguage
-   \ifx\xaskedlanguage\empty \else
-     \ifx\currentmainlanguage\empty\else\resetsystemmode{\systemmodeprefix\currentmainlanguage}\fi
+   \ifempty\xaskedlanguage \else
+     \ifempty\currentmainlanguage\else\resetsystemmode{\systemmodeprefix\currentmainlanguage}\fi
      \let\currentmainlanguage\xaskedlanguage
      \setsystemmode{\systemmodeprefix\currentmainlanguage}%
    \fi
    \edef\xaskedlanguage{#2}%
-   \ifx\xaskedlanguage\empty \else
-     \ifx\currentlanguage\empty\else\resetsystemmode\currentlanguage\fi
+   \ifempty\xaskedlanguage \else
+     \ifempty\currentlanguage\else\resetsystemmode\currentlanguage\fi
      \let\currentlanguage\xaskedlanguage
      \setsystemmode\currentlanguage
    \fi}
@@ -454,7 +454,7 @@
 
 \appendtoks
     \edef\currentlanguagesetups{\languageparameter\c!setups}%
-    \ifx\currentlanguagesetups\empty \else
+    \ifempty\currentlanguagesetups \else
         \setups[\currentlanguagesetups]%
     \fi
 \to \everylanguage
@@ -492,7 +492,7 @@
 
 \appendtoks
     \edef\p_language_font{\languageparameter\s!font}%
-    \ifx\p_language_font\empty
+    \ifempty\p_language_font
     \orelse\ifx\p_language_font\v!auto
       \doaddfeature\currentlanguage
     \else
@@ -513,15 +513,15 @@
 
 \unexpanded\def\uselanguageparameter#1%
   {\edef\askedlanguage{#1\c!language}%
-   \ifx\askedlanguage\empty\else\lang_basics_switch_asked\fi}
+   \ifempty\askedlanguage\else\lang_basics_switch_asked\fi}
 
 \unexpanded\def\douselanguageparameter#1% fast setter
   {\edef\askedlanguage{#1}%
-   \ifx\askedlanguage\empty\else\lang_basics_switch_asked\fi}
+   \ifempty\askedlanguage\else\lang_basics_switch_asked\fi}
 
 \unexpanded\def\lang_basics_set_current[#1]%
   {\edef\askedlanguage{#1}%
-   \ifx\askedlanguage\empty\else\lang_basics_switch_asked\fi}
+   \ifempty\askedlanguage\else\lang_basics_switch_asked\fi}
 
 \unexpanded\def\language
   {\doifelsenextoptionalcs\lang_basics_set_current\normallanguage}
@@ -542,7 +542,7 @@
 
 \unexpanded\def\mainlanguage[#1]%
   {\edef\askedlanguage{#1}%
-   \ifx\askedlanguage\empty
+   \ifempty\askedlanguage
    \orelse\ifcsname\??languagelinked\askedlanguage\endcsname
     %\edef\askedlanguage{\csname\??languagelinked\askedlanguage\endcsname}%
      \edef\askedlanguage{\lastnamedcs}%
@@ -699,7 +699,7 @@
 \def\lang_basics_start_exceptions[#1]#2\stopexceptions % multilingual or not?
   {\begingroup
    \edef\askedlanguage{\reallanguagetag{#1}}%
-   \ifx\askedlanguage\empty
+   \ifempty\askedlanguage
      \let\askedlanguage\currentlanguage
    \fi
    \clf_setlanguageexceptions{\askedlanguage}{#2}%
diff --git a/tex/context/base/mkiv/lang-lab.mkxl b/tex/context/base/mkiv/lang-lab.mkxl
index a527224e9..117aa9e2b 100644
--- a/tex/context/base/mkiv/lang-lab.mkxl
+++ b/tex/context/base/mkiv/lang-lab.mkxl
@@ -223,8 +223,8 @@
 % \def\lang_labels_text_prefix_assign_yes#1[#2,#3,#4]%
 %   {\def\m_lang_labels_left {#2}% no longer an edef ... else \Word undefined expansion issues
 %    \def\m_lang_labels_right{#3}% no longer an edef ... else \Word undefined expansion issues
-%    \ifx\m_lang_labels_right\empty
-%      \ifx\m_lang_labels_left\empty
+%    \ifempty\m_lang_labels_right
+%      \ifempty\m_lang_labels_left
 %        \expandafter\def\csname\??label\currenttextprefixclass:\currenttextprefixtag:#1\endcsname{\empty\empty}%
 %      \else
 %        \expandafter\def\csname\??label\currenttextprefixclass:\currenttextprefixtag:#1\endcsname{{#2}\empty}%
@@ -239,8 +239,8 @@
   {\def\m_lang_labels_left {#2}% no longer an edef ... else \Word undefined expansion issues
    \def\m_lang_labels_right{#3}% no longer an edef ... else \Word undefined expansion issues
    \expandafter\def\csname\??label\currenttextprefixclass:\currenttextprefixtag:#1%
-     \ifx\m_lang_labels_right\empty
-       \ifx\m_lang_labels_left\empty
+     \ifempty\m_lang_labels_right
+       \ifempty\m_lang_labels_left
          \endcsname{\empty\empty}%
        \else
          \endcsname{{#2}\empty}%
diff --git a/tex/context/base/mkiv/lpdf-lmt.lua b/tex/context/base/mkiv/lpdf-lmt.lua
index f4e30274a..43c4c1059 100644
--- a/tex/context/base/mkiv/lpdf-lmt.lua
+++ b/tex/context/base/mkiv/lpdf-lmt.lua
@@ -803,7 +803,7 @@ local flushsave, flushrestore, flushsetmatrix  do
                 rx, sx, sy, ry = tonumber(rx), tonumber(sx), tonumber(sy), tonumber(ry)
                 local tx = pos_h * (1 - rx) - pos_v * sy
                 local ty = pos_v * (1 - ry) - pos_h * sx
-                if nofmatrices > 1 then
+                if nofmatrices > 0 then
                     local t = matrices[nofmatrices]
                     local r_x, s_x, s_y, r_y, te, tf = t[1], t[2], t[3], t[4], t[5], t[6]
                     rx, sx = rx * r_x + sx * s_y, rx * s_x + sx * r_y
diff --git a/tex/context/base/mkiv/math-ini.mkxl b/tex/context/base/mkiv/math-ini.mkxl
index 00f70cf07..9cc3dfe1f 100644
--- a/tex/context/base/mkiv/math-ini.mkxl
+++ b/tex/context/base/mkiv/math-ini.mkxl
@@ -446,7 +446,7 @@
 
 \appendtoks
     \edef\p_stylealternative{\mathematicsparameter\c!stylealternative}%
-    \ifx\p_stylealternative\empty\else
+    \ifempty\p_stylealternative\else
         \clf_presetmathalternate\defaultmathfamily{\p_stylealternative}%
     \fi
 \to \everymathematics
@@ -829,7 +829,7 @@
   {\begingroup
    \usemathematicscolorparameter\c!functioncolor
    \edef\p_functionstyle{\mathematicsparameter\c!functionstyle}%
-   \ifx\p_functionstyle\empty
+   \ifempty\p_functionstyle
      \expandafter\math_mfunction_styled_none
    \orelse\ifcsname\??alternativestyle\p_functionstyle\endcsname
      \doubleexpandafter\math_mfunction_styled_text
@@ -1308,7 +1308,7 @@
      \enabledirectives\disabledirectives[math.virtual.optional]}
 
 \appendtoks
-    \ifx\currentmathematics\empty
+    \ifempty\currentmathematics
         \math_basics_check_compact % less tracing
     \fi
 \to \everysetupmathematics
@@ -1813,7 +1813,7 @@
 % 7 = crampedscriptscript
 
 \def\uncramped#1%
-  {{\ifcase\normalmathstyle
+  {{\ifmathstyle
     \or \displaystyle      \or
     \or \textstyle         \or
     \or \scriptstyle       \or
@@ -1821,7 +1821,7 @@
     #1}}
 
 \def\cramped#1%
-  {{\ifcase\normalmathstyle
+  {{\ifmathstyle
     \crampeddisplaystyle      \or \or % 0 -> 1
     \crampedtextstyle         \or \or % 2 -> 3
     \crampedscriptstyle       \or \or % 4 -> 5
@@ -2040,7 +2040,7 @@
 %D \stoptabulate
 
 \def\triggerdisplaystyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \displaystyle        \or
      \crampeddisplaystyle \or
      \displaystyle        \or
@@ -2052,7 +2052,7 @@
    \fi}
 
 \def\triggertextstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \textstyle        \or
      \crampedtextstyle \or
      \textstyle        \or
@@ -2064,7 +2064,7 @@
    \fi}
 
 \def\triggerscriptstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \scriptstyle        \or
      \crampedscriptstyle \or
      \scriptstyle        \or
@@ -2076,7 +2076,7 @@
    \fi}
 
 \def\triggerscriptscriptstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \scriptscriptstyle        \or
      \crampedscriptscriptstyle \or
      \scriptscriptstyle        \or
@@ -2088,21 +2088,21 @@
    \fi}
 
 \def\triggeruncrampedstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
     \or \displaystyle      \or
     \or \textstyle         \or
     \or \scriptstyle       \or
     \or \scriptscriptstyle \fi}
 
 \def\triggercrampedstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
    \crampeddisplaystyle      \or \or
    \crampedtextstyle         \or \or
    \crampedscriptstyle       \or \or
    \crampedscriptscriptstyle \fi}
 
 \def\triggersmallstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \scriptstyle              \or
      \crampedscriptstyle       \or
      \scriptstyle              \or
@@ -2114,7 +2114,7 @@
     \fi}
 
 \def\triggeruncrampedsmallstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \scriptstyle       \or
      \scriptstyle       \or
      \scriptstyle       \or
@@ -2126,7 +2126,7 @@
     \fi}
 
 \def\triggercrampedsmallstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \crampedscriptstyle       \or
      \crampedscriptstyle       \or
      \crampedscriptstyle       \or
@@ -2138,7 +2138,7 @@
     \fi}
 
 \def\triggerbigstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \displaystyle        \or
      \crampeddisplaystyle \or
      \textstyle           \or
@@ -2150,7 +2150,7 @@
     \fi}
 
 \def\triggeruncrampedbigstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \displaystyle \or
      \displaystyle \or
      \textstyle    \or
@@ -2162,7 +2162,7 @@
     \fi}
 
 \def\triggercrampedbigstyle
-  {\ifcase\normalmathstyle\relax
+  {\ifmathstyle
      \crampeddisplaystyle \or
      \crampeddisplaystyle \or
      \crampedtextstyle    \or
@@ -2265,7 +2265,7 @@
 
 \unexpanded\def\math_style_set#1%
   {\edef\m_math_style_asked{#1}%
-   \ifx\m_math_style_asked\empty \else
+   \ifempty\m_math_style_asked \else
      \math_style_set_indeed
    \fi}
 
@@ -2294,13 +2294,13 @@
 
 \unexpanded\def\setupmathstyle[#1]%
   {\edef\m_math_style_asked{#1}%
-   \ifx\m_math_style_asked\empty \else
+   \ifempty\m_math_style_asked \else
      \math_style_set_indeed
    \fi}
 
 \unexpanded\def\usemathstyleparameter#1% faster local variant
   {\edef\m_math_style_asked{#1\c!mathstyle}%
-   \ifx\m_math_style_asked\empty \else
+   \ifempty\m_math_style_asked \else
      \math_style_set_indeed
    \fi}
 
@@ -2385,7 +2385,7 @@
 
 \unexpanded\def\startmathstyle[#1]%
   {\edef\m_math_style_asked{#1}%
-   \ifx\m_math_style_asked\empty
+   \ifempty\m_math_style_asked
      \let\stopmathstyle\relax
    \else
      \bgroup
@@ -2397,7 +2397,7 @@
 
 \unexpanded\def\startusemathstyleparameter#1%
   {\edef\m_math_style_asked{#1\c!mathstyle}%
-   \ifx\m_math_style_asked\empty
+   \ifempty\m_math_style_asked
      \let\stopusemathstyleparameter\relax
    \else
      \bgroup
@@ -2587,7 +2587,7 @@
 
 \appendtoks
     \edef\p_setups{\mathematicsparameter\c!setups}%
-    \ifx\p_setups\empty\else
+    \ifempty\p_setups\else
         \directsetup\p_setups
     \fi
 \to \everyswitchmathematics
@@ -2779,7 +2779,7 @@
 
 \appendtoks
     \edef\p_domain{\mathematicsparameter\c!domain}%
-    \ifx\p_domain\empty
+    \ifempty\p_domain
         \c_math_domain_attribute\attributeunsetvalue
     \else
         \c_math_domain_attribute\clf_getmathdomain\p_domain\relax
@@ -2905,7 +2905,7 @@
 %    \ifcondition\mdim#1\scriptscriptstyle       \frozen#1\scriptscriptstyle       #2\dimexpr#1\scriptscriptstyle       \relax\fi
 %    \ifcondition\mdim#1\crampedscriptscriptstyle\frozen#1\crampedscriptscriptstyle#2\dimexpr#1\crampedscriptscriptstyle\relax\fi}
 
-% \Umathparameter : 0=zero, 1=set, 2=unset (les stracing clutter this way)
+% \ifmathparameter : 0=zero, 1=set, 2=unset (les stracing clutter this way)
 
 %D New stuff:
 %D
@@ -2914,14 +2914,14 @@
 %D \stoptyping
 
 \unexpanded\def\mathopenupparameter#1#2%
-  {\ifcase\Umathparameter#1\displaystyle            \or\frozen#1\displaystyle            #2#1\displaystyle            \fi
-   \ifcase\Umathparameter#1\crampeddisplaystyle     \or\frozen#1\crampeddisplaystyle     #2#1\crampeddisplaystyle     \fi
-   \ifcase\Umathparameter#1\textstyle               \or\frozen#1\textstyle               #2#1\textstyle               \fi
-   \ifcase\Umathparameter#1\crampedtextstyle        \or\frozen#1\crampedtextstyle        #2#1\crampedtextstyle        \fi
-   \ifcase\Umathparameter#1\scriptstyle             \or\frozen#1\scriptstyle             #2#1\scriptstyle             \fi
-   \ifcase\Umathparameter#1\crampedscriptstyle      \or\frozen#1\crampedscriptstyle      #2#1\crampedscriptstyle      \fi
-   \ifcase\Umathparameter#1\scriptscriptstyle       \or\frozen#1\scriptscriptstyle       #2#1\scriptscriptstyle       \fi
-   \ifcase\Umathparameter#1\crampedscriptscriptstyle\or\frozen#1\crampedscriptscriptstyle#2#1\crampedscriptscriptstyle\fi}
+  {\ifmathparameter#1\displaystyle            \or\frozen#1\displaystyle            #2#1\displaystyle            \fi
+   \ifmathparameter#1\crampeddisplaystyle     \or\frozen#1\crampeddisplaystyle     #2#1\crampeddisplaystyle     \fi
+   \ifmathparameter#1\textstyle               \or\frozen#1\textstyle               #2#1\textstyle               \fi
+   \ifmathparameter#1\crampedtextstyle        \or\frozen#1\crampedtextstyle        #2#1\crampedtextstyle        \fi
+   \ifmathparameter#1\scriptstyle             \or\frozen#1\scriptstyle             #2#1\scriptstyle             \fi
+   \ifmathparameter#1\crampedscriptstyle      \or\frozen#1\crampedscriptstyle      #2#1\crampedscriptstyle      \fi
+   \ifmathparameter#1\scriptscriptstyle       \or\frozen#1\scriptscriptstyle       #2#1\scriptscriptstyle       \fi
+   \ifmathparameter#1\crampedscriptscriptstyle\or\frozen#1\crampedscriptscriptstyle#2#1\crampedscriptscriptstyle\fi}
 
 %D New stuff:
 %D
diff --git a/tex/context/base/mkiv/meta-ini.mkxl b/tex/context/base/mkiv/meta-ini.mkxl
index e08aa560a..0f632c854 100644
--- a/tex/context/base/mkiv/meta-ini.mkxl
+++ b/tex/context/base/mkiv/meta-ini.mkxl
@@ -93,7 +93,7 @@
 \def\meta_start_definitions#1#2\stopMPdefinitions
   {\let\m_meta_saved_instance\currentMPinstance
    \edef\currentMPinstance{#1}%
-   \ifx\currentMPinstance\empty
+   \ifempty\currentMPinstance
      \let\currentMPinstance\defaultMPinstance
    \fi
    \gtoksapp\t_meta_definitions{#2}%
@@ -124,7 +124,7 @@
 \def\meta_start_inclusions_indeed#1#2\stopMPinclusions
   {\let\m_meta_saved_instance\currentMPinstance
    \edef\currentMPinstance{#1}%
-   \ifx\currentMPinstance\empty
+   \ifempty\currentMPinstance
      \let\currentMPinstance\defaultMPinstance
    \fi
    \ifx\m_meta_option\!!plustoken \else
@@ -145,7 +145,7 @@
 \def\meta_inclusions_indeed#1#2%
   {\let\m_meta_saved_instance\currentMPinstance
    \edef\currentMPinstance{#1}%
-   \ifx\currentMPinstance\empty
+   \ifempty\currentMPinstance
      \let\currentMPinstance\defaultMPinstance
    \fi
    \ifx\m_meta_option\!!plustoken \else
@@ -194,7 +194,7 @@
 
 \unexpanded\def\meta_analyze_graphicname_indeed[#1::#2::#3]% instance ::
   {\edef\currentMPgraphicname{#2}%
-   \ifx\currentMPgraphicname\empty
+   \ifempty\currentMPgraphicname
      \edef\currentMPgraphicname{#1}%
      \let\currentMPinstance\defaultMPinstance
    \orelse\ifcsname\??mpdefinitions#1\endcsname
@@ -262,7 +262,7 @@
      \setfalse\c_meta_include_initializations
    \fi
    \edef\p_setups{\MPinstanceparameter\c!setups}%
-   \ifx\p_setups\empty \else
+   \ifempty\p_setups \else
      \setups[\p_setups]%
    \fi
    \useMPinstancestyleparameter\c!textstyle}
@@ -289,7 +289,7 @@
 
 \unexpanded\def\meta_process_graphic_instance#1%
   {\edef\currentMPinstance{#1}%
-   \ifx\currentMPinstance\empty
+   \ifempty\currentMPinstance
      \let\currentMPinstance\defaultMPinstance
    \fi
    \edef\currentMPformat{\MPinstanceparameter\s!format}%
@@ -539,7 +539,7 @@
      {\??graphicvariable\currentmpvariableclass:#1}%
    \edef\m_meta_current_variable
      {\begincsname\m_meta_current_variable_template\endcsname}%
-   \ifx\m_meta_current_variable\empty
+   \ifempty\m_meta_current_variable
      \expandafter\meta_prepare_variable_nop
    \else
      \expandafter\meta_prepare_variable_yes
@@ -557,7 +557,7 @@
       \else
          \begincsname\??graphicvariable\currentMPgraphicname:#1\endcsname
       \fi}%
-   \ifx\m_meta_current_variable\empty
+   \ifempty\m_meta_current_variable
      \expandafter\meta_prepare_variable_nop
    \else
      \expandafter\meta_prepare_variable_yes
@@ -712,7 +712,7 @@
   {\begingroup
    \edef\currentmpvariableclass{#1}%
    \edef\m_meta_instance_variables{#2}%
-   \ifx\m_meta_instance_variables\empty \else
+   \ifempty\m_meta_instance_variables \else
      \meta_prepare_instance_variables
    \fi
    \meta_enable_include % redundant
@@ -745,7 +745,7 @@
   {\begingroup
    \edef\currentmpvariableclass{#1}%
    \edef\m_meta_instance_variables{#2}%
-   \ifx\m_meta_instance_variables\empty \else
+   \ifempty\m_meta_instance_variables \else
      \meta_prepare_instance_variables
    \fi
    \meta_enable_include % redundant
@@ -778,7 +778,7 @@
    \else
      \let\usedMPgraphicname\empty
    \fi
-   \ifx\usedMPgraphicname\empty
+   \ifempty\usedMPgraphicname
      % message
    \else
      \doifsomething{#2}{\setupMPvariables[\usedMPgraphicname][#2]}%
@@ -1072,8 +1072,8 @@
 %D that fails with spot colors.
 
 \startMPinitializations
-    def OverlayLineColor=\ifx\overlaylinecolor\empty black \else\MPcolor{\overlaylinecolor} \fi enddef;
-    def OverlayColor    =\ifx\overlaycolor    \empty black \else\MPcolor{\overlaycolor}     \fi enddef;
+    def OverlayLineColor=\ifempty\overlaylinecolor black \else\MPcolor{\overlaylinecolor} \fi enddef;
+    def OverlayColor    =\ifempty\overlaycolor     black \else\MPcolor{\overlaycolor}     \fi enddef;
 \stopMPinitializations
 
 % \newcount\c_overlay_colormodel
@@ -1448,7 +1448,7 @@
 
 \appendtoks
     \edef\p_mpy{\directMPgraphicsparameter{mpy}}%
-    \ifx\p_mpy\empty \else
+    \ifempty\p_mpy \else
       \let\MPdataMPYfile\p_mpy
       \clf_registermpyfile{\p_mpy}%
     \fi
diff --git a/tex/context/base/mkiv/mult-aux.mkxl b/tex/context/base/mkiv/mult-aux.mkxl
index 7a5e60b29..f8eceb9a1 100644
--- a/tex/context/base/mkiv/mult-aux.mkxl
+++ b/tex/context/base/mkiv/mult-aux.mkxl
@@ -112,7 +112,18 @@
 \def\mult_interfaces_get_parameters_error_indeed#1#2%
   {\showassignerror{#2}{\the\inputlineno\space(#1)}}
 
-\def\mult_interfaces_get_parameters_assign#1=#2=#3#4^^^^0004%
+% \def\mult_interfaces_get_parameters_assign#1=#2=#3#4^^^^0004%
+%   {\ifx\empty#1\empty
+%      \expandafter\mult_interfaces_get_parameters_error
+%    \orelse\ifx#3\empty
+%      \expandafter\mult_interfaces_get_parameters_error
+%    \else
+%      \expandafter\mult_interfaces_adef % assignment def
+%    \fi
+%    \m_mult_interfaces_namespace{#1}{#2}%
+%    \doubleexpandafter\mult_interfaces_get_parameters_item}
+
+\def\mult_interfaces_get_parameters_assign#1=#2=#3#0^^^^0004%
   {\ifx\empty#1\empty
      \expandafter\mult_interfaces_get_parameters_error
    \orelse\ifx#3\empty
@@ -129,13 +140,29 @@
 
     \let\mult_interfaces_get_parameters_error\undefined
 
-    \def\mult_interfaces_get_parameters_error_one#1\csname#2#3\endcsname#4%
+%     \def\mult_interfaces_get_parameters_error_one#1\csname#2#3\endcsname#4%
+%       {\mult_interfaces_get_parameters_error_indeed{#2}{#3}\iftrue}
+
+%     \def\mult_interfaces_get_parameters_error_two#1\csname#2#3\endcsname#4%
+%       {\mult_interfaces_get_parameters_error_indeed{#2}{#3}}
+
+%     \def\mult_interfaces_get_parameters_assign#1=#2=#3#4^^^^0004%
+%       {\ifx\empty#1\empty
+%          \mult_interfaces_get_parameters_error_one
+%        \orelse\ifx#3\empty
+%          \mult_interfaces_get_parameters_error_two
+%        \else
+%          \expandafter\def\csname\m_mult_interfaces_namespace#1\endcsname{#2}%
+%        \fi
+%        \doubleexpandafter\mult_interfaces_get_parameters_item}
+
+    \def\mult_interfaces_get_parameters_error_one#1\csname#2#3\endcsname#0%
       {\mult_interfaces_get_parameters_error_indeed{#2}{#3}\iftrue}
 
-    \def\mult_interfaces_get_parameters_error_two#1\csname#2#3\endcsname#4%
+    \def\mult_interfaces_get_parameters_error_two#1\csname#2#3\endcsname#0%
       {\mult_interfaces_get_parameters_error_indeed{#2}{#3}}
 
-    \def\mult_interfaces_get_parameters_assign#1=#2=#3#4^^^^0004%
+    \def\mult_interfaces_get_parameters_assign#1=#2=#3#0^^^^0004%
       {\ifx\empty#1\empty
          \mult_interfaces_get_parameters_error_one
        \orelse\ifx#3\empty
@@ -149,10 +176,16 @@
 
 \newif\ifassignment
 
-\def\mult_check_for_assignment_indeed#1=#2#3^^^^0004%
+% \def\mult_check_for_assignment_indeed#1=#2#3^^^^0004%
+%   {\if#2^^^^0003\assignmentfalse\else\assignmenttrue\fi}
+
+% \def\mult_check_for_assignment_indeed_begin_#1=#2#3^^^^0004%
+%   {\if#2^^^^0003}
+
+\def\mult_check_for_assignment_indeed#0=#2#0^^^^0004%
   {\if#2^^^^0003\assignmentfalse\else\assignmenttrue\fi}
 
-\def\mult_check_for_assignment_indeed_begin_#1=#2#3^^^^0004%
+\def\mult_check_for_assignment_indeed_begin_#0=#2#0^^^^0004%
   {\if#2^^^^0003}
 
 \def\mult_check_for_assignment#1%
@@ -250,7 +283,8 @@
    \def#5##1##2{\ifx##1\relax\else#4##1{##2}\fi}%
    \def#6{#1#2:}%
    \def#7##1{#1##1:}%
-   \def#8{\ifx#2\empty\orelse\ifcsname#1#2:\s!parent\endcsname\else\expandafter\let\csname#1#2:\s!parent\endcsname#1\fi}%
+  %\def#8{\ifx#2\empty\orelse\ifcsname#1#2:\s!parent\endcsname\else\expandafter\let\csname#1#2:\s!parent\endcsname#1\fi}%
+   \def#8{\ifempty#2\orelse\ifcsname#1#2:\s!parent\endcsname\else\expandafter\let\csname#1#2:\s!parent\endcsname#1\fi}%
    \unexpanded\def#9##1{\expandafter\edef\csname#1##1:\s!parent\endcsname{#1#2}}}
 
 \unexpanded\def\installparameterhashhandler#1#2%
@@ -306,15 +340,19 @@
 \unexpanded\def\mult_interfaces_install_style_and_color_handler#1#2#3#4%
   {\unexpanded\def#2##1##2% style color
      {\edef\currentstyleparameter{#1{##1}}% this name is public (can also set color e.g. in underline)
-      \ifx\currentstyleparameter\empty\else\dousecurrentstyleparameter\fi
+     %\ifx\currentstyleparameter\empty\else\dousecurrentstyleparameter\fi
+      \ifempty\currentstyleparameter\else\dousecurrentstyleparameter\fi
       \edef\currentcolorparameter{#1{##2}}% this name is public (so we do this after the style switch)
-      \ifx\currentcolorparameter\empty\else\dousecurrentcolorparameter\fi}%
+     %\ifx\currentcolorparameter\empty\else\dousecurrentcolorparameter\fi}%
+      \ifempty\currentcolorparameter\else\dousecurrentcolorparameter\fi}%
    \unexpanded\def#3##1% style
      {\edef\currentstyleparameter{#1{##1}}% this name is public
-      \ifx\currentstyleparameter\empty\else\dousecurrentstyleparameter\fi}%
+     %\ifx\currentstyleparameter\empty\else\dousecurrentstyleparameter\fi}%
+      \ifempty\currentstyleparameter\else\dousecurrentstyleparameter\fi}%
    \unexpanded\def#4##1% color
      {\edef\currentcolorparameter{#1{##1}}% this name is public
-      \ifx\currentcolorparameter\empty\else\dousecurrentcolorparameter\fi}}
+     %\ifx\currentcolorparameter\empty\else\dousecurrentcolorparameter\fi}}
+      \ifempty\currentcolorparameter\else\dousecurrentcolorparameter\fi}}
 
 \unexpanded\def\installstyleandcolorhandler#1#2%
   {\normalexpanded
@@ -1044,7 +1082,8 @@
 
 \unexpanded\def\mult_interfaces_install_parent_injector#1#2#3#4%
   {\unexpanded\def#4##1%
-     {\ifx#3\empty
+    %{\ifx#3\empty
+     {\ifempty#3%
         \expandafter\def\csname#1#2:\s!parent\endcsname{#1##1}%
       \fi}}
 
@@ -1058,24 +1097,40 @@
 % Faster but not used that much to make a dent in performance. But, because it's
 % cleaner anyway and also gives less tracing, we apply it a few times.
 
-\unexpanded\def\syst_helpers_install_macro_stack#1#2#3%
-  {\xdef\m_syst_helpers_push_macro{\csstring#1}%
-   \ifcsname#3\m_syst_helpers_push_macro\endcsname\else
-     \expandafter\newcount\csname#3\m_syst_helpers_push_macro\endcsname
-     \expandafter\edef\csname push_macro_\m_syst_helpers_push_macro\endcsname
-       {\noexpand\expandafter\glet
-           \noexpand\csname\m_syst_helpers_push_macro\noexpand\the\csname#3\m_syst_helpers_push_macro\endcsname\endcsname
-           \noexpand#1%
-         \global\advance\csname#3\m_syst_helpers_push_macro\endcsname\plusone}%
-     \expandafter\edef\csname pop_macro_\m_syst_helpers_push_macro\endcsname
-       {\global\advance\csname#3\m_syst_helpers_push_macro\endcsname\minusone
-        \noexpand\expandafter#2%
-           \noexpand\expandafter\noexpand#1%
-           \noexpand\csname\m_syst_helpers_push_macro\noexpand\the\csname#3\m_syst_helpers_push_macro\endcsname\endcsname}%
-   \fi}
+% \unexpanded\def\syst_helpers_install_macro_stack#1#2#3%
+%   {\xdef\m_syst_helpers_push_macro{\csstring#1}%
+%    \ifcsname#3\m_syst_helpers_push_macro\endcsname\else
+%      \expandafter\newcount\csname#3\m_syst_helpers_push_macro\endcsname
+%      \expandafter\edef\csname push_macro_\m_syst_helpers_push_macro\endcsname
+%        {\noexpand\expandafter\glet
+%            \noexpand\csname\m_syst_helpers_push_macro\noexpand\the\csname#3\m_syst_helpers_push_macro\endcsname\endcsname
+%            \noexpand#1%
+%          \global\advance\csname#3\m_syst_helpers_push_macro\endcsname\plusone}%
+%      \expandafter\edef\csname pop_macro_\m_syst_helpers_push_macro\endcsname
+%        {\global\advance\csname#3\m_syst_helpers_push_macro\endcsname\minusone
+%         \noexpand\expandafter#2%
+%            \noexpand\expandafter\noexpand#1%
+%            \noexpand\csname\m_syst_helpers_push_macro\noexpand\the\csname#3\m_syst_helpers_push_macro\endcsname\endcsname}%
+%    \fi}
+%
+% \unexpanded\def\installmacrostack      #1{\syst_helpers_install_macro_stack#1\let \??localpushedmacro }
+% \unexpanded\def\installglobalmacrostack#1{\syst_helpers_install_macro_stack#1\glet\??globalpushedmacro}
+
+% The \LUA\ based variant is twice as fast as the above but as said, we don't use
+% this one that often. It's more about less tracing than speed here.
+
+\unexpanded\def\installmacrostack#1%
+  {\ifdefined#1\else\let#1\empty\fi
+   \unexpanded\expandafter\gdef\csname push_macro_\csstring#1\endcsname{\localpushmacro#1}%
+   \unexpanded\expandafter\gdef\csname  pop_macro_\csstring#1\endcsname{\localpopmacro #1}}
+
+
+\unexpanded\def\installglobalmacrostack#1%
+  {\ifdefined#1\else\glet#1\empty\fi
+   \unexpanded\expandafter\gdef\csname push_macro_\csstring#1\endcsname{\globalpushmacro#1}%
+   \unexpanded\expandafter\gdef\csname  pop_macro_\csstring#1\endcsname{\globalpopmacro #1}}
 
-\unexpanded\def\installmacrostack      #1{\syst_helpers_install_macro_stack#1\let \??localpushedmacro }
-\unexpanded\def\installglobalmacrostack#1{\syst_helpers_install_macro_stack#1\glet\??globalpushedmacro}
+% \showmacrostack can be used to see if there are different entries
 
 %  \unprotect
 %
diff --git a/tex/context/base/mkiv/mult-prm.lua b/tex/context/base/mkiv/mult-prm.lua
index 5a77349c5..469fab85c 100644
--- a/tex/context/base/mkiv/mult-prm.lua
+++ b/tex/context/base/mkiv/mult-prm.lua
@@ -160,7 +160,6 @@ return {
   "Umathoverbarvgap",
   "Umathoverdelimiterbgap",
   "Umathoverdelimitervgap",
-  "Umathparameter",
   "Umathpunctbinspacing",
   "Umathpunctclosespacing",
   "Umathpunctinnerspacing",
@@ -238,6 +237,7 @@ return {
   "aftergrouped",
   "alignmark",
   "aligntab",
+  "atendofgrouped",
   "attribute",
   "attributedef",
   "automaticdiscretionary",
@@ -301,8 +301,11 @@ return {
   "ifcondition",
   "ifcstok",
   "ifdimval",
+  "ifempty",
   "iffrozen",
   "ifincsname",
+  "ifmathparameter",
+  "ifmathstyle",
   "ifnumval",
   "ifprotected",
   "iftok",
@@ -354,6 +357,7 @@ return {
   "mathstyle",
   "mathsurroundmode",
   "mathsurroundskip",
+  "noalignmode",
   "noboundary",
   "nohrule",
   "nokerns",
@@ -522,8 +526,10 @@ return {
   "accent",
   "adjdemerits",
   "advance",
+  "afterassigned",
   "afterassignment",
   "aftergroup",
+  "atendofgroup",
   "atop",
   "atopwithdelims",
   "badness",
@@ -665,6 +671,7 @@ return {
   "leqno",
   "let",
   "limits",
+  "linepar",
   "linepenalty",
   "lineskip",
   "lineskiplimit",
diff --git a/tex/context/base/mkiv/pack-lyr.mkxl b/tex/context/base/mkiv/pack-lyr.mkxl
index 43460092e..419c9f279 100644
--- a/tex/context/base/mkiv/pack-lyr.mkxl
+++ b/tex/context/base/mkiv/pack-lyr.mkxl
@@ -342,7 +342,7 @@
      \let\p_pack_layers_height  \zeropoint
      \let\p_pack_layers_position\v!yes
    \fi
-   \ifx\p_pack_layers_rotation\empty \else
+   \ifempty\p_pack_layers_rotation \else
      % use direct call
      \setbox\nextbox\hpack
        {\rotate[\c!location=\v!high,\c!rotation=\layerparameter\c!rotation]{\box\nextbox}}%
@@ -359,7 +359,7 @@
      \pack_layers_set_last_position_nop
    \fi
    %
-   \ifx\m_pack_layers_page\empty \else % is expanded
+   \ifempty\m_pack_layers_page \else % is expanded
      \edef\m_pack_layers_page{:\m_pack_layers_page}%
      \ifcsname\??layerbox\m_pack_layers_target\currentlayer\m_pack_layers_page\endcsname \else
        \expandafter\newbox\csname\??layerbox\m_pack_layers_target\currentlayer\m_pack_layers_page\endcsname
@@ -670,8 +670,7 @@
    % \edef\p_pack_layers_position{\layerparameter\c!position}% local
    \ifx\p_pack_layers_position\v!yes
      \edef\p_pack_layers_region{\layerparameter\c!region}%
-     \ifx\p_pack_layers_region\empty
-     \else
+     \ifempty\p_pack_layers_region\else
        \anch_mark_tagged_box\nextbox\p_pack_layers_region % was \layeranchor
      \fi
    \fi
diff --git a/tex/context/base/mkiv/pack-rul.mkxl b/tex/context/base/mkiv/pack-rul.mkxl
index 8131c3fc5..4fef06ad0 100644
--- a/tex/context/base/mkiv/pack-rul.mkxl
+++ b/tex/context/base/mkiv/pack-rul.mkxl
@@ -345,7 +345,7 @@
 
 \def\pack_framed_background_box_color
   {\edef\p_framed_backgroundcolor{\framedparameter\c!backgroundcolor}%
-   \ifx\p_framed_backgroundcolor\empty \else
+   \ifempty\p_framed_backgroundcolor \else
      \doifcolor\p_framed_backgroundcolor\pack_framed_background_box_color_indeed
    \fi}
 
@@ -605,7 +605,7 @@
       \d_framed_target_ht\dimexpr\framedbackgroundheight+ \framedbackgroundoffset\relax
       \d_framed_target_dp\dimexpr\framedbackgrounddepth + \framedbackgroundoffset+\framedparameter\c!backgrounddepth\relax
       \let\pack_framed_overlay_initialize\pack_framed_overlay_initialize_indeed
-      \ifx\p_framed_component\empty
+      \ifempty\p_framed_component
         \resetlayoutcomponentattribute
       \else
         \setlayoutcomponentattribute{\v!background:\p_framed_component}%
@@ -663,7 +663,7 @@
       \setbox\b_framed_extra\hpack
         {\kern-\d_framed_frameoffset
          \raise\scratchdimen
-         \hpack{\ifx\overlaylinecolor\empty\else\dousecolorparameter\overlaylinecolor\fi\pack_framed_stroked_box}}%
+         \hpack{\ifempty\overlaylinecolor\else\dousecolorparameter\overlaylinecolor\fi\pack_framed_stroked_box}}%
       \wd\b_framed_extra\wd\b_framed_normal
       \ht\b_framed_extra\ht\b_framed_normal
       \dp\b_framed_extra\dp\b_framed_normal
@@ -920,7 +920,7 @@
    \setbox\b_framed_normal\hbox{#4}%
    \iftrialtypesetting \else
      \edef\m_overlay_region{\framedparameter\c!region}%
-     \ifx\m_overlay_region\empty\else
+     \ifempty\m_overlay_region\else
        \pack_framed_set_region
      \fi
    \fi
@@ -932,12 +932,12 @@
    % not here, in calling macro: setups
    \pack_framed_remove_depth
    \ifx\p_framed_frame\v!overlay \orelse \ifx\p_framed_frame\v!none \else
-     \ifx\p_framed_rulethickness\empty\else
+     \ifempty\p_framed_rulethickness\else
         \d_framed_linewidth\p_framed_rulethickness\relax
      \fi
      \pack_framed_add_outline % real or invisible frame
    \fi
-   \ifx\p_framed_background\empty \else
+   \ifempty\p_framed_background \else
      \edef\p_framed_backgroundoffset{\framedparameter\c!backgroundoffset}%
      \d_framed_backgroundoffset
        \ifx\p_framed_backgroundoffset\v!frame
@@ -949,7 +949,7 @@
      \pack_framed_add_background
    \fi
    \pack_framed_restore_depth
-   \iftrialtypesetting\orelse\ifx\m_overlay_region\empty\else
+   \iftrialtypesetting\orelse\ifempty\m_overlay_region\else
      \pack_framed_add_region
    \fi
    \box\b_framed_normal
@@ -961,7 +961,7 @@
 \unexpanded\def\pack_framed_process_box_indeed#1#2% component box (assumes parameters set and grouped usage)
   {\setbox\b_framed_normal\box#2% could actually be \let\b_framed_normal#2
    \edef\m_overlay_region{\framedparameter\c!region}%
-   \ifx\m_overlay_region\empty\else
+   \ifempty\m_overlay_region\else
      \pack_framed_set_region
    \fi
    \edef\p_framed_rulethickness{\framedparameter\c!rulethickness}% also used in backgrounds
@@ -969,12 +969,12 @@
    \edef\p_framed_frame{\framedparameter\c!frame}%
    \edef\p_framed_background{\framedparameter\c!background}%
    \ifx\p_framed_frame\v!overlay \orelse \ifx\p_framed_frame\v!none \else
-     \ifx\p_framed_rulethickness\empty \else
+     \ifempty\p_framed_rulethickness \else
         \d_framed_linewidth\p_framed_rulethickness\relax
      \fi
      \pack_framed_add_outline % real or invisible frame
    \fi
-   \ifx\p_framed_background\empty \else
+   \ifempty\p_framed_background \else
      \edef\p_framed_backgroundoffset{\framedparameter\c!backgroundoffset}%
      \d_framed_backgroundoffset
        \ifx\p_framed_backgroundoffset\v!frame
@@ -985,7 +985,7 @@
      \edef\p_framed_component{#1}%
      \pack_framed_add_background
    \fi
-   \ifx\m_overlay_region\empty\else
+   \ifempty\m_overlay_region\else
      \pack_framed_add_region
    \fi
    \box\b_framed_normal
@@ -1073,7 +1073,7 @@
    \framedparameter\c!extras
    % to get the right spacing
    \edef\p_framed_foregroundstyle{\framedparameter\c!foregroundstyle}%
-   \ifx\p_framed_foregroundstyle\empty\else\dousestyleparameter\p_framed_foregroundstyle\fi
+   \ifempty\p_framed_foregroundstyle\else\dousestyleparameter\p_framed_foregroundstyle\fi
    % beware, both the frame and background offset can be overruled
    %
    \edef\p_framed_setups{\framedparameter\c!setups}%
@@ -1103,7 +1103,7 @@
    \fi
    \ifconditional\c_framed_has_frame
      \edef\p_framed_rulethickness{\framedparameter\c!rulethickness}%
-     \ifx\p_framed_rulethickness\empty\else
+     \ifempty\p_framed_rulethickness\else
         \d_framed_linewidth\p_framed_rulethickness\relax
      \fi
    \else
@@ -1116,7 +1116,7 @@
    %
    \forgetall % should happen after \localwidth but before align
    %
-   \ifx\localformat\empty
+   \ifempty\localformat
      \setfalse\c_framed_has_format
    \else
      \settrue\c_framed_has_format
@@ -1143,7 +1143,7 @@
      % obey user set height, also downward compatible
    \else
      \edef\p_framed_lines{\framedparameter\c!lines}%
-     \ifx\p_framed_lines\empty
+     \ifempty\p_framed_lines
      \orelse\ifcase\p_framed_lines
      \else
        \d_framed_height\p_framed_lines\lineheight
@@ -1226,7 +1226,7 @@
    \fi
    \pack_framed_check_extra_offsets
    \edef\p_framed_background{\framedparameter\c!background}%
-%    \ifx\p_framed_background\empty
+%    \ifempty\p_framed_background
 %      \let\pack_framed_forgetall\forgetall
 %    \else
 %      \let\pack_framed_forgetall\relax
@@ -1235,7 +1235,7 @@
    \edef\framedwidth {\the\ifdim\d_framed_width >\zeropoint         \d_framed_width \else\zeropoint\fi}% public
    \edef\framedheight{\the\ifdim\d_framed_height>\zeropoint         \d_framed_height\else\zeropoint\fi}% public
    \edef\framedoffset{\the\dimexpr\ifconditional\c_framed_has_offset\localoffset    \else\zeropoint\fi}% public
-   \ifx\p_framed_orientation\empty
+   \ifempty\p_framed_orientation
      \let\pack_framed_stop_orientation\relax
    \else
      \pack_framed_start_orientation
@@ -1419,7 +1419,7 @@
 \def\doassigncheckedframeoffset#1#2% could be a fast \csname .. \endcsname
   {\edef\checkedframeoffset{#2}%
    #1%
-     \ifx\checkedframeoffset\empty    \zeropoint\orelse
+     \ifempty\checkedframeoffset      \zeropoint\orelse
      \ifx\checkedframeoffset\v!overlay\zeropoint\orelse
      \ifx\checkedframeoffset\v!none   \zeropoint\orelse
      \ifx\checkedframeoffset\v!frame  \zeropoint\orelse
@@ -1493,7 +1493,7 @@
    \ifconditional\c_framed_has_format
     %\ifconditional\c_framed_has_height \else
     %  \edef\p_profile{\framedparameter\c!profile}%
-    %  \ifx\p_profile\empty\else
+    %  \ifempty\p_profile\else
     %    \pack_framed_profile_box
     %  \fi
     %\fi
@@ -1512,7 +1512,7 @@
      \fi
      \ifconditional\c_framed_has_height \else
        \edef\p_profile{\framedparameter\c!profile}%
-       \ifx\p_profile\empty\else
+       \ifempty\p_profile\else
          \pack_framed_profile_box
        \fi
      \fi
@@ -1530,7 +1530,7 @@
      \ht\b_framed_normal\d_framed_height
    \else
      \edef\p_framed_minheight{\framedparameter\c!minheight}%
-     \ifx\p_framed_minheight\empty \else
+     \ifempty\p_framed_minheight \else
        \ifdim\ht\b_framed_normal<\p_framed_minheight
          \ht\b_framed_normal\p_framed_minheight
        \fi
@@ -1540,13 +1540,13 @@
    \ifx\p_framed_empty\v!yes
      \pack_framed_fake_box
    \fi
-   \ifx\p_framed_anchoring\empty\else
+   \ifempty\p_framed_anchoring\else
      \pack_framed_handle_anchoring
    \fi
    \pack_framed_stop_orientation % moved here at 2014-05-25
    \iftrialtypesetting \else
      \edef\m_overlay_region{\framedparameter\c!region}%
-     \ifx\m_overlay_region\empty\else
+     \ifempty\m_overlay_region\else
        \pack_framed_set_region
      \fi
    \fi
@@ -1579,14 +1579,14 @@
      \ifconditional\c_framed_has_frame % real or invisible frame
        \pack_framed_add_outline
      \fi
-     \ifx\p_framed_background\empty \else
+     \ifempty\p_framed_background \else
        \edef\p_framed_component{\framedparameter\c!component}%
        \pack_framed_add_background
      \fi
    \fi
    \pack_framed_locator_after\p_framed_location
    \iftrialtypesetting \else
-     \ifx\m_overlay_region\empty\else
+     \ifempty\m_overlay_region\else
        \pack_framed_add_region
      \fi
    \fi
@@ -1630,8 +1630,8 @@
       % using the keyword approachs works ok, don't mess with orientation
       % directly here using \boxorientation ... it doesn't work that well
       \s!orientation\scratchcounter
-      \ifx\p_xanchor\empty\else \s!xoffset \p_xanchor\fi
-      \ifx\p_yanchor\empty\else \s!yoffset \p_yanchor\fi
+      \ifempty\p_xanchor\else \s!xoffset \p_xanchor\fi
+      \ifempty\p_yanchor\else \s!yoffset \p_yanchor\fi
      {\box\b_framed_normal}}}
 
 \installcorenamespace{framedlocatorbefore}
@@ -2172,10 +2172,10 @@
 
 \def\pack_framed_set_foregroundcolor
   {\edef\p_framed_foregroundcolor{\framedparameter\c!foregroundcolor}%
-   \ifx\p_framed_foregroundcolor\empty\else\dousecolorparameter\p_framed_foregroundcolor\fi}
+   \ifempty\p_framed_foregroundcolor\else\dousecolorparameter\p_framed_foregroundcolor\fi}
 
 \def\pack_framed_do_setups
-  {\ifx\p_framed_setups\empty \else
+  {\ifempty\p_framed_setups \else
      \setups[\p_framed_setups]% \texsetup (or only one!)
    % \fastsetup\p_framed_setup % singular would have been better
    \fi}
@@ -2197,6 +2197,7 @@
        \bgroup
        \synchronizeinlinedirection
        \localbegstrut
+      %\aftergrouped{\localendstrut\pack_framed_do_bottom\egroup}%
        \aftergroup\localendstrut
        \aftergroup\pack_framed_do_bottom
        \aftergroup\egroup
@@ -3083,7 +3084,7 @@
      \immediateassignment\edef\tempstring{#1\c!bottomframe}\ifx\tempstring\v!on      +\plusone\fi
      \immediateassignment\edef\tempstring{#1\c!leftframe  }\ifx\tempstring\v!on      +\plusone\fi
      \immediateassignment\edef\tempstring{#1\c!rightframe }\ifx\tempstring\v!on      +\plusone\fi
-     \immediateassignment\edef\tempstring{#1\c!background }\ifx\tempstring\empty\else+\plusone\fi
+     \immediateassignment\edef\tempstring{#1\c!background }\ifempty\tempstring\else+\plusone\fi
    \relax\expandafter\secondoftwoarguments\else\expandafter\firstoftwoarguments\fi}
 
 \protect \endinput
diff --git a/tex/context/base/mkiv/page-txt.mklx b/tex/context/base/mkiv/page-txt.mklx
index b8184e443..ff582e561 100644
--- a/tex/context/base/mkiv/page-txt.mklx
+++ b/tex/context/base/mkiv/page-txt.mklx
@@ -88,7 +88,7 @@
    \fi}
 
 \appendtoks
-    \ifx\currentlayoutelement\empty\else
+    \ifempty\currentlayoutelement\else
         \page_layouts_synchronize_element\currentlayoutelement % brr, can be vertical:horizontal
     \fi
 \to \everysetuplayoutelement
@@ -251,7 +251,7 @@
    \begincsname\??layouttextstrut\layoutelementparameter\c!strut\endcsname
    \ignorecrlf
    \edef\currentlayoutelementwidth{\layoutelementparameter#width}%
-   \ifx\currentlayoutelementwidth\empty\else
+   \ifempty\currentlayoutelementwidth\else
      \expandafter\page_layouts_process_element_limited
    \fi\p_text
    \endgroup}
@@ -500,7 +500,7 @@
 
 \def\page_layouts_left_edge_element_indeed#text#style#color#width%
   {\letfromlayoutelementparameter\p_text#text%
-   \ifx\p_text\empty
+   \ifempty\p_text
      \kern\leftedgewidth
    \else
       \hbox to \leftedgewidth\bgroup
@@ -517,7 +517,7 @@
 
 \def\page_layouts_right_edge_element_indeed#text#style#color#width%
   {\letfromlayoutelementparameter\p_text#text%
-   \ifx\p_text\empty
+   \ifempty\p_text
      \kern\rightedgewidth
    \else
       \hbox to \rightedgewidth\bgroup
@@ -536,7 +536,7 @@
 
 \def\page_layouts_left_margin_element_indeed#text#style#color#width#margintoo%
   {\letfromlayoutelementparameter\p_text#text%
-   \ifx\p_text\empty
+   \ifempty\p_text
      \kern\leftmarginwidth
    \else
      \hbox to \leftmarginwidth\bgroup
@@ -546,7 +546,7 @@
    \fi
    \ifcase#margintoo\or
      \letfromlayoutelementparameter\p_text\c!margintext
-     \ifx\p_text\empty\else
+     \ifempty\p_text\else
        \kern-\leftmarginwidth
        \hbox to \leftmarginwidth\bgroup
          \hss
@@ -563,7 +563,7 @@
 
 \def\page_layouts_right_margin_element_indeed#text#style#color#width#margintoo%
   {\letfromlayoutelementparameter\p_text#text%
-   \ifx\p_text\empty
+   \ifempty\p_text
      \kern\rightmarginwidth
    \else
      \hbox to \rightmarginwidth\bgroup
@@ -573,7 +573,7 @@
    \fi
    \ifcase#margintoo\or
      \letfromlayoutelementparameter\p_text\c!margintext
-     \ifx\p_text\empty\else
+     \ifempty\p_text\else
        \kern-\rightmarginwidth
        \hbox to \rightmarginwidth\bgroup
          \p_text % ? styling
@@ -590,8 +590,8 @@
 
 \def\page_layouts_text_body_element_indeed_l_m_r_e
   {\letfromlayoutelementparameter\p_text\c!lefttext
-   \ifx\p_text\empty
-     \ifx\page_layouts_place_extra_text_left\empty\else
+   \ifempty\p_text
+     \ifempty\page_layouts_place_extra_text_left\else
        \hbox to \makeupwidth\bgroup
          \page_layouts_place_extra_text_left
          \hss
@@ -607,7 +607,7 @@
      \kern-\makeupwidth
    \fi
    \letfromlayoutelementparameter\p_text\c!middletext
-   \ifx\p_text\empty\else
+   \ifempty\p_text\else
      \hbox to \makeupwidth\bgroup
        \hss
        \page_layouts_process_element_indeed\c!middlestyle\c!middlecolor\c!middlewidth
@@ -616,7 +616,7 @@
      \kern-\makeupwidth
    \fi
    \letfromlayoutelementparameter\p_text\c!righttext
-   \ifx\p_text\empty
+   \ifempty\p_text
      \kern\makeupwidth
    \else
      \hbox to \makeupwidth\bgroup
@@ -627,7 +627,7 @@
 
 \def\page_layouts_text_body_element_indeed_e_r_m_l
   {\letfromlayoutelementparameter\p_text\c!righttext
-   \ifx\p_text\empty\else
+   \ifempty\p_text\else
      \hbox to \makeupwidth\bgroup
        \page_layouts_process_element_indeed\c!rightstyle\c!rightcolor\c!rightwidth
        \hss
@@ -635,7 +635,7 @@
      \kern-\makeupwidth
    \fi
    \letfromlayoutelementparameter\p_text\c!middletext
-   \ifx\p_text\empty\else
+   \ifempty\p_text\else
      \hbox to \makeupwidth\bgroup
        \hss
        \page_layouts_process_element_indeed\c!middlestyle\c!middlecolor\c!middlewidth
@@ -644,8 +644,8 @@
      \kern-\makeupwidth
    \fi
    \letfromlayoutelementparameter\p_text\c!lefttext
-   \ifx\p_text\empty
-     \ifx\page_layouts_place_extra_text_right\empty
+   \ifempty\p_text
+     \ifempty\page_layouts_place_extra_text_right
        \kern\makeupwidth
      \else
        \hbox to \makeupwidth\bgroup
@@ -824,7 +824,7 @@
    \else
      \let\m_page_layouts_page_number_location\p_strc_pagenumbers_location
      \page_layouts_reset_page_number_location
-     \ifx\p_strc_pagenumbers_location\empty
+     \ifempty\p_strc_pagenumbers_location
        % set otherwise
      \orelse\ifx\p_strc_pagenumbers_location\v!none
        % set otherwise
@@ -839,7 +839,7 @@
    \setbox\scratchbox\hbox{\ignorespaces\layoutelementparameter\c!marginedgetext\removeunwantedspaces}%
    \ifzeropt\wd\scratchbox\else
      \edef\p_strc_pagenumbers_width{\directpagenumberingparameter\c!width}%
-     \ifx\p_strc_pagenumbers_width\empty
+     \ifempty\p_strc_pagenumbers_width
        \box\scratchbox\tfskip
      \else
        \hpack to \p_strc_pagenumbers_width{\box\scratchbox\hss}%
@@ -852,7 +852,7 @@
    \setbox\scratchbox\hbox{\ignorespaces\layoutelementparameter\c!marginedgetext\removeunwantedspaces}%
    \ifzeropt\wd\scratchbox\else
      \edef\p_strc_pagenumbers_width{\directpagenumberingparameter\c!width}%
-     \ifx\p_strc_pagenumbers_width\empty
+     \ifempty\p_strc_pagenumbers_width
        \tfskip\box\scratchbox
      \else
        \hpack to \p_strc_pagenumbers_width{\hss\box\scratchbox}%
diff --git a/tex/context/base/mkiv/spac-hor.mkiv b/tex/context/base/mkiv/spac-hor.mkiv
index 0f65eea33..5c7163822 100644
--- a/tex/context/base/mkiv/spac-hor.mkiv
+++ b/tex/context/base/mkiv/spac-hor.mkiv
@@ -210,12 +210,12 @@
 
 %D Here come the handlers (still rather messy ... we need states).
 
-\newif\ifindentation \indentationtrue  % will become a mode
+%newif\ifindentation \indentationtrue  % will become a mode
 
 \let\checkindentation\relax
 
 \installmacrostack\checkindentation
-\installmacrostack\ifindentation
+%installmacrostack\ifindentation
 
 \def\spac_indentation_remove
   {\ifzeropt\parindent \else
@@ -225,20 +225,20 @@
    \fi}
 
 \def\spac_indentation_kill_indeed
-  {\global\indentationfalse
+  {%\global\indentationfalse
    \spac_indentation_remove}
 
 \def\spac_indentation_do_toggle_indeed
-  {\global\indentationfalse
+  {%\global\indentationfalse
    \glet\checkindentation\spac_indentation_no_toggle_indeed
    \spac_indentation_remove}
 
 \def\spac_indentation_no_toggle_indeed
-  {\global\indentationtrue
+  {%\global\indentationtrue
    \glet\checkindentation\spac_indentation_do_toggle_indeed}
 
 \def\spac_indentation_do_indeed
-  {\global\indentationtrue}
+  {}%\global\indentationtrue}
 
 \def\spac_indentation_do_toggle
   {\glet\checkindentation\spac_indentation_do_toggle_indeed}
@@ -264,13 +264,13 @@
 
 \def\spac_indentation_variant_no % made global
   {\ifinpagebody \else
-     \global\indentationfalse
+     %\global\indentationfalse
      \glet\checkindentation\spac_indentation_no_next_check
    \fi}
 
 \def\nonoindentation % bv bij floats
   {\ifinpagebody \else
-     \global\indentationtrue
+     %\global\indentationtrue
      \glet\checkindentation\spac_indentation_do_indeed
    \fi}
 
diff --git a/tex/context/base/mkiv/spac-ver.mkiv b/tex/context/base/mkiv/spac-ver.mkiv
index 6ed1847c5..e75ea4e1b 100644
--- a/tex/context/base/mkiv/spac-ver.mkiv
+++ b/tex/context/base/mkiv/spac-ver.mkiv
@@ -2655,6 +2655,8 @@
 % test \par
 % test \par
 
+% only main vertical list
+
 \unexpanded\def\ignoreparskip{\c_spac_vspacing_ignore_parskip\plusone}
 
 \protect \endinput
diff --git a/tex/context/base/mkiv/spac-ver.mkxl b/tex/context/base/mkiv/spac-ver.mkxl
index 0151fe311..f719e1f09 100644
--- a/tex/context/base/mkiv/spac-ver.mkxl
+++ b/tex/context/base/mkiv/spac-ver.mkxl
@@ -88,7 +88,7 @@
   {\edef\normallineheight{\interlinespaceparameter\c!line}%
    \iflocalinterlinespace \else
      \edef\m_spac_normallineheight{\bodyfontinterlinespace}%
-     \ifx\m_spac_normallineheight\empty \else
+     \ifempty\m_spac_normallineheight \else
        \let\normallineheight\m_spac_normallineheight
      \fi
    \fi}
@@ -144,7 +144,7 @@
    \fi}
 
 \def\spac_linespacing_set_relative_interlinespace
-  {\ifx\currentrelativeinterlinespace\empty\else
+  {\ifempty\currentrelativeinterlinespace\else
      \spacing\currentrelativeinterlinespace
    \fi}
 
@@ -158,7 +158,7 @@
 
 \unexpanded\def\useinterlinespaceparameter#1% see footnotes
   {\edef\m_spac_interlinespace{#1\c!interlinespace}%
-   \ifx\m_spac_interlinespace\empty \else
+   \ifempty\m_spac_interlinespace \else
      \spac_linespacing_setup_use
    \fi}
 
@@ -210,7 +210,7 @@
 
 \unexpanded\def\dosetupcheckedinterlinespace#1% often a chain
   {\edef\p_spac_checked_interlinespace{#1}%
-   \ifx\p_spac_checked_interlinespace\empty
+   \ifempty\p_spac_checked_interlinespace
      \spac_linespacing_synchronize_local
    \orelse\ifcsname\namedinterlinespacehash\p_spac_checked_interlinespace\s!parent\endcsname % we could have a \s!check
      \push_macro_currentinterlinespace
@@ -373,7 +373,7 @@
 
 \def\spac_whitespace_setup_yes[#1]%
   {\edef\m_spac_whitespace_asked{#1}%
-   \ifx\m_spac_whitespace_asked\empty
+   \ifempty\m_spac_whitespace_asked
      \spac_whitespace_setup_nop
    \else
      \let\v_spac_whitespace_current\m_spac_whitespace_asked
@@ -1524,7 +1524,7 @@
 
 \def\spac_grids_expand_snapper#1%
   {\edef\m_spac_snapper
-     {\ifx\m_spac_snapper\empty\else\m_spac_snapper,\fi
+     {\ifempty\m_spac_snapper\else\m_spac_snapper,\fi
       \ifcsname\??gridsnappersets#1\endcsname
         \lastnamedcs\else#1%
       \fi}}
@@ -1546,7 +1546,7 @@
 
 \unexpanded\def\usegridparameter#1% no checking here
   {\edef\m_spac_grid_asked{#1\c!grid}%
-   \ifx\m_spac_grid_asked\empty
+   \ifempty\m_spac_grid_asked
      \attribute \snapvboxattribute\attributeunsetvalue
    \else
      \spac_grids_snap_value_set\m_spac_grid_asked
@@ -1742,7 +1742,7 @@
      \spac_grids_check_nop
    \orelse\ifx\askedgridmode\v!off % for taco and luigi
      \spac_grids_check_nop
-   \orelse\ifx\askedgridmode\empty % to be sure
+   \orelse\ifempty\askedgridmode % to be sure
      \spac_grids_check_nop
    \else
      \spac_grids_check_yes
@@ -1753,12 +1753,12 @@
 
 \unexpanded\def\checkgridmethod#1%
   {\edef\p_grid{#1}%
-   \ifx\p_grid\empty
+   \ifempty\p_grid
      \let\checkedgridmethod\empty
      \let\checkedgridscope \v!local
    \else
      \splitatcolon\p_grid\checkedgridscope\checkedgridmethod
-     \ifx\checkedgridmethod\empty
+     \ifempty\checkedgridmethod
        \ifx\checkedgridscope\v!local\orelse\ifx\checkedgridscope\v!global\else
          \let\checkedgridmethod\checkedgridscope
          \let\checkedgridscope \v!local
@@ -1769,7 +1769,7 @@
 \unexpanded\def\applygridmethod#1#2#3% content localsettings (used in head rendering)
    {\checkgridmethod{#1}%
     \ifx\checkedgridscope\v!global
-      \ifx\checkedgridmethod\empty \else
+      \ifempty\checkedgridmethod \else
         % we assume that the call is grouped because grouping here has the side
         % effect that the eventually constructed line will get the value outside
         % the group
@@ -1784,7 +1784,7 @@
       % we really need that in this case (compatibility etc etc) so here we don't
       % het an already done hit (otherwise we would not snap)
       \hbox\bgroup
-        \ifx\checkedgridmethod\empty\orelse\ifconditional\headisdisplay
+        \ifempty\checkedgridmethod\orelse\ifconditional\headisdisplay
           #2%
         \fi
         \snaptogrid[\checkedgridmethod]\hbox{#3}%
@@ -2165,7 +2165,7 @@
 
 \unexpanded\def\useblankparameter#1% faster local variant
   {\edef\m_spac_blank_asked{#1\c!blank}%
-   \ifx\m_spac_blank_asked\empty\else
+   \ifempty\m_spac_blank_asked\else
      \directvspacing\m_spac_blank_asked
    \fi}
 
@@ -2200,7 +2200,7 @@
   }
 
 \def\setupvspacing_nop
-  {\ifx\empty\currentvspacing % mistakenly had an \else
+  {\ifempty\currentvspacing % mistakenly had an \else
      \let\currentvspacing\s!default
    \fi
    \spac_whitespace_setup_nop}
@@ -2426,7 +2426,7 @@
      {\let\m_spac_hanging_location\empty
       \setupcurrenthanging[#1]}%
      {\edef\m_spac_hanging_location{#1}}%
-   \ifx\m_spac_hanging_location\empty
+   \ifempty\m_spac_hanging_location
      \edef\m_spac_hanging_location{\directhangingparameter\c!location}%
    \fi
    \dowithnextboxcs\spac_hanging_finish\hbox}
@@ -2552,7 +2552,7 @@
 
 \unexpanded\def\checkedblank[#1]%
   {\edef\p_blank{#1}%
-   \ifx\p_blank\empty
+   \ifempty\p_blank
      % ignore
    \orelse\ifx\p_blank\v!none
      % ignore
@@ -2569,7 +2569,7 @@
 \unexpanded\def\prerollblank[#1]%
   {\begingroup
    \edef\p_blank{#1}%
-   \ifx\p_blank\empty
+   \ifempty\p_blank
      \global\prerolledblank\zeropoint
    \orelse\ifx\p_blank\v!none
      \global\prerolledblank\zeropoint
diff --git a/tex/context/base/mkiv/status-files.pdf b/tex/context/base/mkiv/status-files.pdf
index fe106c62b..d153ea9cd 100644
--- a/tex/context/base/mkiv/status-files.pdf
+++ b/tex/context/base/mkiv/status-files.pdf
diff --git a/tex/context/base/mkiv/status-lua.pdf b/tex/context/base/mkiv/status-lua.pdf
index 551550e7d..eb92931f3 100644
--- a/tex/context/base/mkiv/status-lua.pdf
+++ b/tex/context/base/mkiv/status-lua.pdf
diff --git a/tex/context/base/mkiv/strc-itm.mklx b/tex/context/base/mkiv/strc-itm.mklx
index 60fe3ee74..2f3cc8425 100644
--- a/tex/context/base/mkiv/strc-itm.mklx
+++ b/tex/context/base/mkiv/strc-itm.mklx
@@ -248,12 +248,12 @@
 % todo: \dodosetreference -> \strc_counters_register_component (to be checked)
 
 \def\strc_itemgroups_insert_reference % we will make a decent number helper
-  {\iftrialtypesetting \orelse \ifx\currentitemreference \empty \else
+  {\iftrialtypesetting \orelse \ifempty\currentitemreference \else
      \strc_itemgroups_insert_reference_indeed
    \fi}
 
 \def\strc_itemgroups_insert_extra_reference
-  {\iftrialtypesetting \orelse \ifx\currentitemreference \empty \else
+  {\iftrialtypesetting \orelse \ifempty\currentitemreference \else
      \normalexpanded{\textreference[\currentitemreference]{\strc_itemgroups_extra_symbol}}%
    \fi}
 
@@ -396,9 +396,9 @@
 
 \def\strc_itemgroups_process_option#option%
   {\edef\itemgroupconstantvalue{#option}%
-   \ifx\itemgroupconstantvalue\empty\else
+   \ifempty\itemgroupconstantvalue\else
      \splitatasterisk\itemgroupconstantvalue\itemgroupfirst\itemgroupsecond
-     \ifx\itemgroupsecond\empty
+     \ifempty\itemgroupsecond
         \let\itemgroupsecond\itemgroupfirst
         \let\itemgroupfirst\!!plusone
      \fi
@@ -424,7 +424,7 @@
 \setvalue{\??itemgroupkeyword\v!unpacked   }{\strc_itemgroups_process_set_option_unpack}
 \setvalue{\??itemgroupkeyword\v!intro      }{\settrue\c_strc_itemgroups_intro} % here? not set to false
 \setvalue{\??itemgroupkeyword\v!autointro  }{\settrue\c_strc_itemgroups_auto_intro}
-\setvalue{\??itemgroupkeyword\v!broad      }{\ifx\itemgroupfirst\empty
+\setvalue{\??itemgroupkeyword\v!broad      }{\ifempty\itemgroupfirst
                                                \let\itemgroupfirst\!!plusone
                                              \fi
                                              \letitemgroupparameter\c!factor\itemgroupfirst}
@@ -450,7 +450,7 @@
 \setvalue{\??itemgroupkeyword\v!joinedup   }{\settrue\c_strc_itemgroups_joined
                                              \strc_itemgroups_process_set_option_pack}
 \setvalue{\??itemgroupkeyword\v!notjoinedup}{\setfalse\c_strc_itemgroups_joined}
-\setvalue{\??itemgroupkeyword\v!serried    }{\edef\itemgroupfirst{-\ifx\itemgroupfirst\empty1\else\itemgroupfirst\fi}%
+\setvalue{\??itemgroupkeyword\v!serried    }{\edef\itemgroupfirst{-\ifempty\itemgroupfirst1\else\itemgroupfirst\fi}%
                                              \letitemgroupparameter\c!factor\itemgroupfirst}
 \setvalue{\??itemgroupkeyword\v!stopper    }{\letitemgroupparameter\c!placestopper\v!yes} % keep {}
 \setvalue{\??itemgroupkeyword\v!nostopper  }{\letitemgroupparameter\c!placestopper\v!no} % keep {}
@@ -658,7 +658,7 @@
 
 \def\strc_itemgroups_increment_item_counter
   {\ifconditional\c_strc_itemgroups_sub \else
-     \ifconditional\c_strc_itemgroups_symbol \else % \ifx\strc_itemgroups_extra_symbol\empty
+     \ifconditional\c_strc_itemgroups_symbol \else % \ifempty\strc_itemgroups_extra_symbol
        \strc_counters_increment_sub\v_strc_itemgroups_counter\currentitemlevel
      \fi
    \fi}
@@ -733,7 +733,7 @@
 
 \def\strc_itemgroups_set_symbol#symbol%
   {\edef\strc_itemgroups_tmp_symbol{#symbol}%
-   \ifx\strc_itemgroups_tmp_symbol\empty \else
+   \ifempty\strc_itemgroups_tmp_symbol \else
      \doifelsesymboldefined\strc_itemgroups_tmp_symbol
         \strc_itemgroups_set_symbol_symbol
         {\doifelseconversiondefined\strc_itemgroups_tmp_symbol
@@ -813,9 +813,9 @@
 \def\strc_itemgroups_start_indeed[#options][#settings]%
   {\edef\itemgroupoptions{\itemgroupparameter\c!option}%
    \edef\itemgroupextraoptions{#options}%
-   \ifx\itemgroupoptions\empty
+   \ifempty\itemgroupoptions
      \let\itemgroupoptions\itemgroupextraoptions
-   \orelse\ifx\itemgroupextraoptions\empty
+   \orelse\ifempty\itemgroupextraoptions
      % ok
    \else
      \edef\itemgroupoptions{\itemgroupoptions,\itemgroupextraoptions}%
@@ -844,7 +844,7 @@
    \fi
    \c_strc_itemgroups_n_of_items\zerocount
    \strc_itemgroups_check_n_of_items
-   \ifx\itemgroupoptions\empty
+   \ifempty\itemgroupoptions
      \strc_itemgroups_setup_symbol_default
      \strc_itemgroups_reset_continue_state
      \setupcurrentitemgroup[#settings]%
@@ -896,9 +896,9 @@
        \strc_counters_restart_sub\v_strc_itemgroups_counter\currentitemlevel{\numexpr\itemgroupparameter\c!start-\plusone\relax}%
      \fi
    \fi
-   \ifx\strc_itemgroups_used_symbol\empty
+   \ifempty\strc_itemgroups_used_symbol
      \strc_itemgroups_set_symbol\strc_itemgroups_asked_symbol % ** default value
-     \ifx\strc_itemgroups_used_symbol\empty
+     \ifempty\strc_itemgroups_used_symbol
        \let\currentitemgroupsymbol\currentitemlevel % ** fall back
      \fi
    \fi
@@ -932,7 +932,7 @@
        \advance\leftskip\d_strc_itemgroups_list_width\relax
      \fi
    \fi
-   \ifx\m_strc_itemgroups_repeat_start\empty
+   \ifempty\m_strc_itemgroups_repeat_start
      \let\currentitemgroupconversionset \currentitemgroupsymbol
      \edef\currentitemgroupsegments     {\currentitemlevel}%
    \else
@@ -1453,13 +1453,13 @@
         {\box\b_strc_itemgroups\hskip\itemgroupparameter\c!distance}}}
 
 \def\strc_itemgroups_make_destination_box
-  {\iftrialtypesetting \orelse \ifx\m_strc_itemgroups_destination\empty \else
+  {\iftrialtypesetting \orelse \ifempty\m_strc_itemgroups_destination \else
      \setbox\b_strc_itemgroups\hbox{\directgotobox{\box\b_strc_itemgroups}[\m_strc_itemgroups_destination]}%
    \fi}
 
 \def\strc_itemgroups_check_indenting
   {\setfalse\c_strc_itemgroups_indented_first
-   \ifx\m_strc_itemgroups_indenting\empty \else
+   \ifempty\m_strc_itemgroups_indenting \else
      \normalexpanded{\setupindenting[\v!reset,\v!yes,\m_strc_itemgroups_indenting]}%
      \ifconditional\c_spac_indentation_indent_first % better is to have a mode
        \doifnot{\itemgroupparameter\c!alignsymbol}\v!yes
@@ -1469,7 +1469,7 @@
 
 \def\strc_itemgroups_check_for_repeated
   {\ifconditional\c_strc_itemgroups_repeat
-     \ifx\m_strc_itemgroups_repeat_start\empty
+     \ifempty\m_strc_itemgroups_repeat_start
        \edef\m_strc_itemgroups_repeat_start{\currentitemlevel}%
      \fi
    \else
@@ -1546,7 +1546,7 @@
 
 \unexpanded\def\strc_itemgroups_set_text_item_distance
   {\edef\m_strc_itemgroups_text_distance{\itemgroupparameter\c!textdistance}%
-   \ifx\m_strc_itemgroups_text_distance\empty
+   \ifempty\m_strc_itemgroups_text_distance
      %
    \orelse\ifcsname\??itemgroupdistance\m_strc_itemgroups_text_distance\endcsname
      \lastnamedcs
diff --git a/tex/context/base/mkiv/supp-box.mkxl b/tex/context/base/mkiv/supp-box.mkxl
index 912eefc63..454e1fab7 100644
--- a/tex/context/base/mkiv/supp-box.mkxl
+++ b/tex/context/base/mkiv/supp-box.mkxl
@@ -1252,7 +1252,7 @@
 %
 % \unexpanded\def\limitatetext#1#2#3% \expanded added 2003/01/16
 %   {\splitatcomma{#2}\leftlimit\rightlimit
-%    \ifx\rightlimit\empty
+%    \ifempty\rightlimit
 %      \normallimitatetext {#1}\leftlimit           {#3}%
 %    \else
 %      \speciallimitatetext{#1}\leftlimit\rightlimit{#3}%
@@ -1262,7 +1262,7 @@
   {\splitatcomma{#2}\leftlimit\rightlimit
    \limitated
       left     \leftlimit
-  \ifx\rightlimit\empty\else
+  \ifempty\rightlimit\else
       right    \rightlimit
   \fi
       strip    true
diff --git a/tex/context/base/mkiv/syst-aux.lua b/tex/context/base/mkiv/syst-aux.lua
index e28e23be0..09232488d 100644
--- a/tex/context/base/mkiv/syst-aux.lua
+++ b/tex/context/base/mkiv/syst-aux.lua
@@ -409,7 +409,12 @@ implement {
     arguments = "integer",
     actions   = function(n)
         statistics.stoptiming("whatever")
-        context("%0.9f",statistics.elapsed("whatever")/(n > 0 and n or 1))
+        local t = statistics.elapsed("whatever")/(n > 0 and n or 1)
+        if t > 0 then
+            context("%0.9f",t)
+        else
+            context(0)
+        end
     end
 }
 
@@ -835,3 +840,99 @@ implement {
     public  = true,
     actions = function() getshape("widowpenalties") end,
 }
+
+if CONTEXTLMTXMODE > 0 then
+
+    -- This is kind of tricky and might not work for all csnames but as long as we use
+    -- it in a controlled way, we're okay. The engine implementation might be changed
+    -- a bit (no need to go through strings, but fetching a cs index and passing that
+    -- back also takes time).
+
+    -- Another approach is to have the predefined stack operate use private stacks and
+    -- then the pop doesn't need the cs. But ... we then also need to store stuff in
+    -- the format so that complicates maters more than I'm willing to do.
+
+    local insert, remove = table.insert, table.remove
+
+    local push_macro  = token.push_macro
+    local pop_macro   = token.pop_macro
+    local scan_csname = token.scan_csname
+
+    local stack = table.setmetatableindex("table")
+
+    local report = logs.reporter("system","macrostack")
+
+    local function pushmacro(name,global)
+        local s = push_macro(name,global)
+        if s then
+            insert(stack[name],s)
+        else
+            report("no macro %a",name)
+            insert(stack[name],false)
+        end
+    end
+
+    local function popmacro(name)
+        local s = remove(stack[name])
+        if s then
+            pop_macro(s)
+        else
+            -- error
+        end
+    end
+
+    tokens.pushmacro = pushmacro
+    tokens.popmacro  = popmacro
+
+    interfaces.implement {
+        name      = "localpushmacro",
+        public    = true,
+        protected = true,
+        actions   = function()
+            pushmacro(scan_csname())
+        end
+    }
+
+    interfaces.implement {
+        name      = "globalpushmacro",
+        public    = true,
+        protected = true,
+        actions   = function()
+            pushmacro(scan_csname(),true)
+        end
+    }
+
+    interfaces.implement {
+        name      = "localpopmacro",
+        public    = true,
+        protected = true,
+        actions   = function()
+            popmacro(scan_csname())
+        end
+    }
+
+    interfaces.implement {
+        name      = "globalpopmacro",
+        public    = true,
+        protected = true,
+        actions   = function()
+            popmacro(scan_csname())
+        end
+    }
+
+   interfaces.implement {
+        name      = "showmacrostack",
+        public    = true,
+        protected = true,
+        actions   = function()
+            local n = scan_csname()
+            local s = stack[n]
+            local m = #s
+            report("%s : %i stack slots used",n,m)
+            for i=1,m do
+                report("% 3i %S",i,s[i])
+            end
+        end
+    }
+
+end
diff --git a/tex/context/base/mkiv/syst-aux.mkxl b/tex/context/base/mkiv/syst-aux.mkxl
index be48007c9..1506e26b1 100644
--- a/tex/context/base/mkiv/syst-aux.mkxl
+++ b/tex/context/base/mkiv/syst-aux.mkxl
@@ -194,22 +194,38 @@
 %D The next set of macros just do nothing, except that they get rid of a number of
 %D arguments.
 
-\def\gobbleoneargument   #1{}
-\def\gobbletwoarguments  #1#2{}
-\def\gobblethreearguments#1#2#3{}
-\def\gobblefourarguments #1#2#3#4{}
-\def\gobblefivearguments #1#2#3#4#5{}
-\def\gobblesixarguments  #1#2#3#4#5#6{}
-\def\gobblesevenarguments#1#2#3#4#5#6#7{}
-\def\gobbleeightarguments#1#2#3#4#5#6#7#8{}
-\def\gobbleninearguments #1#2#3#4#5#6#7#8#9{}
-\def\gobbletenarguments  #1{\gobbleninearguments}
-
-\def\gobbleoneoptional   [#1]{}
-\def\gobbletwooptionals  [#1][#2]{}
-\def\gobblethreeoptionals[#1][#2][#3]{}
-\def\gobblefouroptionals [#1][#2][#3][#4]{}
-\def\gobblefiveoptionals [#1][#2][#3][#4][#5]{}
+% \def\gobbleoneargument   #1{}
+% \def\gobbletwoarguments  #1#2{}
+% \def\gobblethreearguments#1#2#3{}
+% \def\gobblefourarguments #1#2#3#4{}
+% \def\gobblefivearguments #1#2#3#4#5{}
+% \def\gobblesixarguments  #1#2#3#4#5#6{}
+% \def\gobblesevenarguments#1#2#3#4#5#6#7{}
+% \def\gobbleeightarguments#1#2#3#4#5#6#7#8{}
+% \def\gobbleninearguments #1#2#3#4#5#6#7#8#9{}
+% \def\gobbletenarguments  #1{\gobbleninearguments}
+
+% \def\gobbleoneoptional   [#1]{}
+% \def\gobbletwooptionals  [#1][#2]{}
+% \def\gobblethreeoptionals[#1][#2][#3]{}
+% \def\gobblefouroptionals [#1][#2][#3][#4]{}
+% \def\gobblefiveoptionals [#1][#2][#3][#4][#5]{}
+
+\def\gobbleoneargument               #0{}
+\def\gobbletwoarguments            #0#0{}
+\def\gobblethreearguments        #0#0#0{}
+\def\gobblefourarguments       #0#0#0#0{}
+\def\gobblefivearguments       #0#0#0#0{}
+\def\gobblesixarguments        #0#0#0#0{}
+\def\gobblesevenarguments    #0#0#0#0#0{}
+\def\gobbleeightarguments  #0#0#0#0#0#0{}
+\def\gobbleninearguments #0#0#0#0#0#0#0{}
+
+\def\gobbleoneoptional   [#0]{}
+\def\gobbletwooptionals  [#0][#0]{}
+\def\gobblethreeoptionals[#0][#0][#0]{}
+\def\gobblefouroptionals [#0][#0][#0][#0]{}
+\def\gobblefiveoptionals [#0][#0][#0][#0][#0]{}
 
 %D Reserved macros for tests:
 
@@ -667,7 +683,7 @@
 
 \unexpanded\def\doifelseempty#1%
   {\def\m_syst_string_one{#1}%
-   \ifx\m_syst_string_one\empty
+   \ifempty\m_syst_string_one
      \expandafter\firstoftwoarguments
    \else
      \expandafter\secondoftwoarguments
@@ -677,7 +693,7 @@
 
 \unexpanded\def\doifempty#1%
   {\def\m_syst_string_one{#1}%
-   \ifx\m_syst_string_one\empty
+   \ifempty\m_syst_string_one
      \expandafter\firstofoneargument
    \else
      \expandafter\gobbleoneargument
@@ -685,7 +701,7 @@
 
 \unexpanded\def\doifnotempty#1%
   {\def\m_syst_string_one{#1}%
-   \ifx\m_syst_string_one\empty
+   \ifempty\m_syst_string_one
      \expandafter\gobbleoneargument
    \else
      \expandafter\firstofoneargument
@@ -1017,7 +1033,7 @@
 
 \unexpanded\def\processaction[#1]#2[%
   {\edef\m_syst_string_one{#1}%
-   \ifx\m_syst_string_one\empty
+   \ifempty\m_syst_string_one
      \let\syst_helpers_do_compare_process_action\syst_helpers_do_compare_process_action_a
    \else
      \let\syst_helpers_do_compare_process_action\syst_helpers_do_compare_process_action_b
@@ -1042,7 +1058,7 @@
 
 \unexpanded\def\processfirstactioninset[#1]%
   {\edef\m_syst_string_one{#1}%
-   \ifx\m_syst_string_one\empty
+   \ifempty\m_syst_string_one
      \expandafter\processaction
    \else
      \expandafter\syst_helpers_process_first_action_in_set_indeed
@@ -1077,7 +1093,7 @@
 
 \unexpanded\def\processallactionsinset[#1]%
   {\edef\m_syst_string_one{#1}%
-   \ifx\m_syst_string_one\empty
+   \ifempty\m_syst_string_one
      \expandafter\processaction
    \else
      \expandafter\syst_helpers_process_all_actions_in_set_indeed
@@ -1140,7 +1156,7 @@
 
 \unexpanded\def\doifelseinstring#1%
   {\edef\m_syst_sub_string{#1}% expand #1 here
-   \ifx\m_syst_sub_string\empty
+   \ifempty\m_syst_sub_string
      \expandafter\thirdofthreearguments
    \else
      \expandafter\syst_helpers_do_if_in_string_else_indeed
@@ -1157,7 +1173,7 @@
 
 \unexpanded\def\doifinstring#1%%
   {\edef\m_syst_sub_string{#1}% expand #1 here
-   \ifx\m_syst_sub_string\empty
+   \ifempty\m_syst_sub_string
      \expandafter\gobbletwoarguments
    \else
      \expandafter\syst_helpers_do_if_in_string_indeed
@@ -1172,7 +1188,7 @@
 
 \unexpanded\def\doifnotinstring#1%%
   {\edef\m_syst_sub_string{#1}% expand #1 here
-   \ifx\m_syst_sub_string\empty
+   \ifempty\m_syst_sub_string
      \expandafter\gobbletwoarguments
    \else
      \expandafter\syst_helpers_do_if_not_in_string_indeed
@@ -1296,7 +1312,7 @@
 
 \unexpanded\def\makerawcommalist[#1]#2% use \processnext ... here
   {\def\syst_helpers_do_make_raw_comma_list##1% we don't expand ##1
-     {\ifx#2\empty
+     {\ifempty#2%
         \def#2{##1}%
       \else
         \expandafter\def\expandafter#2\expandafter{#2,##1}%
@@ -1385,7 +1401,7 @@
   {\edef\m_syst_string_one{#1}%
    \edef\m_syst_string_two{undefined}% better \!!undefined
    \let\m_syst_helpers_process_action\m_syst_string_two
-   \ifx\m_syst_string_one\empty
+   \ifempty\m_syst_string_one
      \expandafter\syst_helpers_do_raw_process_action\expandafter[\s!default][#3]%
    \else
       \expandafter\syst_helpers_do_raw_process_action\expandafter[\m_syst_string_one][#3]%
@@ -2607,41 +2623,77 @@
 %D The next six macros (dedicated to Taco) can conveniently used to select
 %D arguments. Their names explain their functionality.
 
+% \def\firstofoneargument            #1{#1}
+%
+% \def\firstoftwoarguments         #1#2{#1}
+% \def\secondoftwoarguments        #1#2{#2}
+%
+% \def\firstofthreearguments     #1#2#3{#1}
+% \def\secondofthreearguments    #1#2#3{#2}
+% \def\thirdofthreearguments     #1#2#3{#3}
+%
+% \def\firstoffourarguments    #1#2#3#4{#1}
+% \def\secondoffourarguments   #1#2#3#4{#2}
+% \def\thirdoffourarguments    #1#2#3#4{#3}
+% \def\fourthoffourarguments   #1#2#3#4{#4}
+%
+% \def\firstoffivearguments  #1#2#3#4#5{#1}
+% \def\secondoffivearguments #1#2#3#4#5{#2}
+% \def\thirdoffivearguments  #1#2#3#4#5{#3}
+% \def\fourthoffivearguments #1#2#3#4#5{#4}
+% \def\fifthoffivearguments  #1#2#3#4#5{#5}
+%
+% \def\firstofsixarguments #1#2#3#4#5#6{#1}
+% \def\secondofsixarguments#1#2#3#4#5#6{#2}
+% \def\thirdofsixarguments #1#2#3#4#5#6{#3}
+% \def\fourthofsixarguments#1#2#3#4#5#6{#4}
+% \def\fifthofsixarguments #1#2#3#4#5#6{#5}
+% \def\sixthofsixarguments #1#2#3#4#5#6{#6}
+
 \def\firstofoneargument            #1{#1}
 
-\def\firstoftwoarguments         #1#2{#1}
-\def\secondoftwoarguments        #1#2{#2}
+\def\firstoftwoarguments         #1#0{#1}
+\def\secondoftwoarguments        #0#2{#2}
 
-\def\firstofthreearguments     #1#2#3{#1}
-\def\secondofthreearguments    #1#2#3{#2}
-\def\thirdofthreearguments     #1#2#3{#3}
+\def\firstofthreearguments     #1#0#0{#1}
+\def\secondofthreearguments    #0#2#0{#2}
+\def\thirdofthreearguments     #0#0#3{#3}
 
-\def\firstoffourarguments    #1#2#3#4{#1}
-\def\secondoffourarguments   #1#2#3#4{#2}
-\def\thirdoffourarguments    #1#2#3#4{#3}
-\def\fourthoffourarguments   #1#2#3#4{#4}
+\def\firstoffourarguments    #1#0#0#0{#1}
+\def\secondoffourarguments   #0#2#0#0{#2}
+\def\thirdoffourarguments    #0#0#3#0{#3}
+\def\fourthoffourarguments   #0#0#0#4{#4}
 
-\def\firstoffivearguments  #1#2#3#4#5{#1}
-\def\secondoffivearguments #1#2#3#4#5{#2}
-\def\thirdoffivearguments  #1#2#3#4#5{#3}
-\def\fourthoffivearguments #1#2#3#4#5{#4}
-\def\fifthoffivearguments  #1#2#3#4#5{#5}
+\def\firstoffivearguments  #1#0#0#0#0{#1}
+\def\secondoffivearguments #0#2#0#0#0{#2}
+\def\thirdoffivearguments  #0#0#3#0#0{#3}
+\def\fourthoffivearguments #0#0#0#4#0{#4}
+\def\fifthoffivearguments  #0#0#0#0#5{#5}
 
-\def\firstofsixarguments #1#2#3#4#5#6{#1}
-\def\secondofsixarguments#1#2#3#4#5#6{#2}
-\def\thirdofsixarguments #1#2#3#4#5#6{#3}
-\def\fourthofsixarguments#1#2#3#4#5#6{#4}
-\def\fifthofsixarguments #1#2#3#4#5#6{#5}
-\def\sixthofsixarguments #1#2#3#4#5#6{#6}
+\def\firstofsixarguments #1#0#0#0#0#0{#1}
+\def\secondofsixarguments#0#2#0#0#0#0{#2}
+\def\thirdofsixarguments #0#0#3#0#0#0{#3}
+\def\fourthofsixarguments#0#0#0#4#0#0{#4}
+\def\fifthofsixarguments #0#0#0#0#5#0{#5}
+\def\sixthofsixarguments #0#0#0#0#0#6{#6}
+
+% \unexpanded\def\firstofoneunexpanded       #1{#1}
+%
+% \unexpanded\def\firstoftwounexpanded     #1#2{#1}
+% \unexpanded\def\secondoftwounexpanded    #1#2{#2}
+%
+% \unexpanded\def\firstofthreeunexpanded #1#2#3{#1}
+% \unexpanded\def\secondofthreeunexpanded#1#2#3{#2}
+% \unexpanded\def\thirdofthreeunexpanded #1#2#3{#3}
 
 \unexpanded\def\firstofoneunexpanded       #1{#1}
 
-\unexpanded\def\firstoftwounexpanded     #1#2{#1}
-\unexpanded\def\secondoftwounexpanded    #1#2{#2}
+\unexpanded\def\firstoftwounexpanded     #1#0{#1}
+\unexpanded\def\secondoftwounexpanded    #0#2{#2}
 
-\unexpanded\def\firstofthreeunexpanded #1#2#3{#1}
-\unexpanded\def\secondofthreeunexpanded#1#2#3{#2}
-\unexpanded\def\thirdofthreeunexpanded #1#2#3{#3}
+\unexpanded\def\firstofthreeunexpanded #1#0#0{#1}
+\unexpanded\def\secondofthreeunexpanded#0#2#0{#2}
+\unexpanded\def\thirdofthreeunexpanded #0#0#3{#3}
 
 %D \macros
 %D   {globalletempty,letempty,
@@ -4414,7 +4466,7 @@
 \unexpanded\def\removetoks#1\from#2%
   {\def\syst_helpers_remove_toks##1#1##2\empty\empty\empty##3^^^^0004%
      {\def\m_syst_string_one{##3}%
-      \ifx\m_syst_string_one\empty#2{##1}\else#2{##1##2}\fi}%
+      \ifempty\m_syst_string_one#2{##1}\else#2{##1##2}\fi}%
    \expandafter\syst_helpers_remove_toks\the#2\empty\empty\empty#1\empty\empty\empty^^^^0004}
 
 %D Also:
@@ -4481,7 +4533,7 @@
   {\def\syst_helpers_split_string##1#2##2\empty\empty\empty##3\\%
      {\def#3{##1}%
       \def\syst_helpers_split_string{##3}%
-      \ifx\syst_helpers_split_string\empty
+      \ifempty\syst_helpers_split_string
         \let#4\empty
       \else
         \def#4{##2}%
@@ -4495,7 +4547,7 @@
    \let#4\empty
    \doloop
      {\expandafter\splitstring\asciib\at#2\to\asciia\and\asciib
-      \ifx\asciib\empty
+      \ifempty\asciib
         \exitloop
       \else
         % not \edef#3{\ifx#3\empty\else#3#2\fi\asciia} else
@@ -4503,7 +4555,7 @@
         \edef#3{\ifcase\recurselevel\or\else#3#2\fi\asciia}%
         \let#4\asciib
       \fi}%
-  \ifx#3\empty\let#3\asciic\fi}
+  \ifempty#3\let#3\asciic\fi}
 
 %D \macros
 %D   {beforetestandsplitstring,
@@ -4512,17 +4564,17 @@
 
 \unexpanded\def\beforetestandsplitstring#1\at#2\to#3%
   {\def\syst_helpers_split_string##1#2##2#2##3##4\\%
-     {\ifx##3\empty\let#3\empty\else\def#3{##1}\fi}%
+     {\ifempty##3\let#3\empty\else\def#3{##1}\fi}%
    \expandafter\syst_helpers_split_string#1#2#2\empty\\}
 
 \unexpanded\def\aftertestandsplitstring#1\at#2\to#3%
   {\def\syst_helpers_split_string ##1#2##2@@@##3##4\\%
-     {\ifx##3\empty\let#3\empty\else\def#3{##2}\fi}%
+     {\ifempty##3\let#3\empty\else\def#3{##2}\fi}%
    \expandafter\syst_helpers_split_string #1@@@#2@@@\empty\\}
 
 \def\testandsplitstring#1\at#2\to#3\and#4%
   {\def\syst_helpers_split_string##1#2##2#2##3##4\\%
-     {\ifx##3\empty\let#3\empty\let#4\empty\else\def#3{##1}\def#4{##2}\fi}%
+     {\ifempty##3\let#3\empty\let#4\empty\else\def#3{##1}\def#4{##2}\fi}%
    \expandafter\syst_helpers_split_string#1#2#2\empty\\}
 
 %D \macros
@@ -4613,18 +4665,18 @@
 %D The faster alternatives are:
 
 \unexpanded\def\appendtocommalist#1#2%
-  {\dodoglobal\edef#2{\ifx#2\empty\else#2,\fi#1}}
+  {\dodoglobal\edef#2{\ifempty#2\else#2,\fi#1}}
 
 \unexpanded\def\prependtocommalist#1#2%
-  {\dodoglobal\edef#2{#1\ifx#2\empty\else,#2\fi}}
+  {\dodoglobal\edef#2{#1\ifempty#2\else,#2\fi}}
 
 \unexpanded\def\addtocommalist#1#2% {item} \cs
   {\rawdoifelseinset{#1}#2\resetglobal
-     {\dodoglobal\edef#2{\ifx#2\empty\else#2,\fi#1}}}
+     {\dodoglobal\edef#2{\ifempty#2\else#2,\fi#1}}}
 
 \unexpanded\def\pretocommalist#1#2% {item} \cs
   {\rawdoifelseinset{#1}#2\resetglobal
-     {\dodoglobal\edef#2{#1\ifx#2\empty\else,#2\fi}}}
+     {\dodoglobal\edef#2{#1\ifempty#2\else,#2\fi}}}
 
 \unexpanded\def\robustdoifelseinset#1#2%
   {\edef\m_syst_string_one{\detokenize\expandafter{\normalexpanded{#1}}}%
@@ -4635,11 +4687,11 @@
 
 \unexpanded\def\robustaddtocommalist#1#2% {item} \cs
   {\robustdoifelseinset{#1}#2\resetglobal
-     {\dodoglobal\edef#2{\ifx#2\empty\else#2,\fi#1}}}
+     {\dodoglobal\edef#2{\ifempty#2\else#2,\fi#1}}}
 
 \unexpanded\def\robustpretocommalist#1#2% {item} \cs
   {\robustdoifelseinset{#1}#2\resetglobal
-     {\dodoglobal\edef#2{#1\ifx#2\empty\else,#2\fi}}}
+     {\dodoglobal\edef#2{#1\ifempty#2\else,#2\fi}}}
 
 \unexpanded\def\xsplitstring#1#2% \cs {str}
   {\def\syst_helpers_split_string##1,#2,##2,#2,##3\\%
@@ -4655,10 +4707,10 @@
   {\rawdoifelseinset{#1}#2%
      {\normalexpanded{\xsplitstring\noexpand#2{#1}}%
       \dodoglobal\edef#2%
-        {\ifx\m_syst_string_one\empty
+        {\ifempty\m_syst_string_one
            \m_syst_string_two
          \else
-           \m_syst_string_one\ifx\m_syst_string_two\empty\else,\m_syst_string_two\fi
+           \m_syst_string_one\ifempty\m_syst_string_two\else,\m_syst_string_two\fi
          \fi}}
      \resetglobal}
 
@@ -4674,11 +4726,11 @@
 \def\syst_helpers_substitute_in_comma_list_step#1%
   {\edef\m_syst_string_three{#1}%
    \ifx\m_syst_string_one\m_syst_string_three
-     \ifx\m_syst_string_two\empty \else
-       \edef\m_syst_string_four{\ifx\m_syst_string_four\empty\else\m_syst_string_four,\fi\m_syst_string_two}%
+     \ifempty\m_syst_string_two \else
+       \edef\m_syst_string_four{\ifempty\m_syst_string_four\else\m_syst_string_four,\fi\m_syst_string_two}%
      \fi
    \else
-     \edef\m_syst_string_four{\ifx\m_syst_string_four\empty\else\m_syst_string_four,\fi#1}%
+     \edef\m_syst_string_four{\ifempty\m_syst_string_four\else\m_syst_string_four,\fi#1}%
    \fi}
 
 \unexpanded\def\substituteincommalist#1#2#3% old, new, list (slooow)
@@ -4717,8 +4769,8 @@
 
 \def\syst_helpers_replace_in_comma_list_step#1%
   {\ifnum\commalistcounter=\c_syst_helpers_comma_list_index\relax
-     \ifx\newcommalistelement\empty\else
-       \ifx\m_syst_helpers_comma_list_target\empty
+     \ifempty\newcommalistelement\else
+       \ifempty\m_syst_helpers_comma_list_target
          \let\m_syst_helpers_comma_list_target\newcommalistelement
        \else
          \expandafter\expandafter\expandafter\def\expandafter\expandafter\expandafter
@@ -4728,7 +4780,7 @@
      \fi
      \def\commalistelement{#1}%
    \else
-     \ifx\m_syst_helpers_comma_list_target\empty
+     \ifempty\m_syst_helpers_comma_list_target
        \ifx\nexttoken\bgroup % is known -)
          \def\m_syst_helpers_comma_list_target{{#1}}%
        \else
@@ -4845,50 +4897,50 @@
 %D
 %D Beware: global!
 
-\installsystemnamespace{localpushedmacro}
-\installsystemnamespace{globalpushedmacro}
-
-\let\m_syst_helpers_push_macro\empty
-
-\newcount\c_syst_helpers_pop_count
-
-\def\syst_helpers_push_macro_new_global
-  {\expandafter\newcount\csname\??globalpushedmacro\m_syst_helpers_push_macro\endcsname
-   \global\advance\csname\??globalpushedmacro\m_syst_helpers_push_macro\endcsname\plusone}
-
-\def\syst_helpers_push_macro_new_local
-  {\expandafter\newcount\csname\??localpushedmacro\m_syst_helpers_push_macro\endcsname
-   \global\advance\csname\??localpushedmacro\m_syst_helpers_push_macro\endcsname\plusone}
-
-\unexpanded\def\globalpushmacro#1%
-  {\xdef\m_syst_helpers_push_macro{\csstring#1}%
-   \ifcsname\??globalpushedmacro\m_syst_helpers_push_macro\endcsname
-     \global\advance\lastnamedcs\plusone
-   \else
-     \syst_helpers_push_macro_new_global
-   \fi
-   \expandafter\glet\csname\the\lastnamedcs\m_syst_helpers_push_macro\endcsname#1}
-
-\unexpanded\def\localpushmacro#1% this one can be used to push a value over an \egroup
-  {\xdef\m_syst_helpers_push_macro{\csstring#1}%
-   \ifcsname\??localpushedmacro\m_syst_helpers_push_macro\endcsname
-     \global\advance\lastnamedcs\plusone
-   \else
-     \syst_helpers_push_macro_new_local
-   \fi
-   \expandafter\glet\csname\the\lastnamedcs\m_syst_helpers_push_macro\endcsname#1}
-
-\unexpanded\def\globalpopmacro#1%
-  {\xdef\m_syst_helpers_push_macro{\csstring#1}%
-   \c_syst_helpers_pop_count\csname\??globalpushedmacro\m_syst_helpers_push_macro\endcsname
-   \global\advance\lastnamedcs \minusone
-   \expandafter\glet\expandafter#1\csname\the\c_syst_helpers_pop_count\m_syst_helpers_push_macro\endcsname}
-
-\unexpanded\def\localpopmacro#1%
-  {\xdef\m_syst_helpers_push_macro{\csstring#1}%
-   \c_syst_helpers_pop_count\csname\??localpushedmacro\m_syst_helpers_push_macro\endcsname
-   \global\advance\lastnamedcs \minusone
-   \expandafter\let\expandafter#1\csname\the\c_syst_helpers_pop_count\m_syst_helpers_push_macro\endcsname}
+% \installsystemnamespace{localpushedmacro}
+% \installsystemnamespace{globalpushedmacro}
+%
+% \let\m_syst_helpers_push_macro\empty
+%
+% \newcount\c_syst_helpers_pop_count
+%
+% \def\syst_helpers_push_macro_new_global
+%   {\expandafter\newcount\csname\??globalpushedmacro\m_syst_helpers_push_macro\endcsname
+%    \global\advance\csname\??globalpushedmacro\m_syst_helpers_push_macro\endcsname\plusone}
+%
+% \def\syst_helpers_push_macro_new_local
+%   {\expandafter\newcount\csname\??localpushedmacro\m_syst_helpers_push_macro\endcsname
+%    \global\advance\csname\??localpushedmacro\m_syst_helpers_push_macro\endcsname\plusone}
+%
+% \unexpanded\def\globalpushmacro#1%
+%   {\xdef\m_syst_helpers_push_macro{\csstring#1}%
+%    \ifcsname\??globalpushedmacro\m_syst_helpers_push_macro\endcsname
+%      \global\advance\lastnamedcs\plusone
+%    \else
+%      \syst_helpers_push_macro_new_global
+%    \fi
+%    \expandafter\glet\csname\the\lastnamedcs\m_syst_helpers_push_macro\endcsname#1}
+%
+% \unexpanded\def\localpushmacro#1% this one can be used to push a value over an \egroup
+%   {\xdef\m_syst_helpers_push_macro{\csstring#1}%
+%    \ifcsname\??localpushedmacro\m_syst_helpers_push_macro\endcsname
+%      \global\advance\lastnamedcs\plusone
+%    \else
+%      \syst_helpers_push_macro_new_local
+%    \fi
+%    \expandafter\glet\csname\the\lastnamedcs\m_syst_helpers_push_macro\endcsname#1}
+%
+% \unexpanded\def\globalpopmacro#1%
+%   {\xdef\m_syst_helpers_push_macro{\csstring#1}%
+%    \c_syst_helpers_pop_count\csname\??globalpushedmacro\m_syst_helpers_push_macro\endcsname
+%    \global\advance\lastnamedcs \minusone
+%    \expandafter\glet\expandafter#1\csname\the\c_syst_helpers_pop_count\m_syst_helpers_push_macro\endcsname}
+%
+% \unexpanded\def\localpopmacro#1%
+%   {\xdef\m_syst_helpers_push_macro{\csstring#1}%
+%    \c_syst_helpers_pop_count\csname\??localpushedmacro\m_syst_helpers_push_macro\endcsname
+%    \global\advance\lastnamedcs \minusone
+%    \expandafter\let\expandafter#1\csname\the\c_syst_helpers_pop_count\m_syst_helpers_push_macro\endcsname}
 
 \let\pushmacro\localpushmacro
 \let\popmacro \localpopmacro
@@ -5028,7 +5080,7 @@
 %D Also handy:
 
 \def\doifelseemptyvalue#1%
-  {\expandafter\ifx\csname#1\endcsname\empty
+  {\expandafter\ifempty\csname#1\endcsname
      \expandafter\firstoftwoarguments
    \else
      \expandafter\secondoftwoarguments
@@ -5037,14 +5089,14 @@
 \let\doifemptyvalueelse\doifelseemptyvalue
 
 \def\doifemptyvalue#1%
-  {\expandafter\ifx\csname#1\endcsname\empty
+  {\expandafter\ifempty\csname#1\endcsname
      \expandafter\firstofoneargument
    \else
      \expandafter\gobbleoneargument
    \fi}
 
 \def\doifnotemptyvalue#1%
-  {\expandafter\ifx\csname#1\endcsname\empty
+  {\expandafter\ifempty\csname#1\endcsname
      \expandafter\gobbleoneargument
    \else
      \expandafter\firstofoneargument
@@ -6125,7 +6177,7 @@
 \unexpanded\def\syst_helpers_if_has_space_else#1 #2#3\relax % \space\empty\relax
   {\ifx\m_syst_string_one\space
      \expandafter\firstoftwoarguments
-   \orelse\ifx#2\empty
+   \orelse\ifempty#2%
      \expandafter\secondoftwoarguments
    \else
      \expandafter\firstoftwoarguments
@@ -6255,11 +6307,16 @@
    \c_syst_helpers_test_feature_n\zerocount
    \syst_helpers_test_feature_nop
    \clf_benchmarktimer
-   \writestatus\m!system{starting feature test (n=\number\c_syst_helpers_test_feature_m)}\wait
+   \writestatus\m!system
+     {starting feature test: %
+      \number\c_syst_helpers_test_feature_m\space steps}%
    \c_syst_helpers_test_feature_n\zerocount
    \syst_helpers_test_feature_yes
-   \writestatus\m!system{\number\c_syst_helpers_test_feature_m\space feature tests done (\elapsedseconds s)}%
-   \wait
+   \writestatus\m!system
+     {feature test done: %
+      \number\c_syst_helpers_test_feature_m\space steps, %
+      \clf_elapsedtime\space seconds, %
+      \clf_elapsedsteptime\elapsedsteps\space\space per step}%
    \egroup}
 
 \unexpanded\def\showtimer#1%
@@ -6327,7 +6384,7 @@
 
 \def\syst_helpers_with_range#1%
   {\splitstring#1\at:\to\m_syst_helpers_range_from\and\m_syst_helpers_range_to
-   \ifx\m_syst_helpers_range_to\empty\let\m_syst_helpers_range_to\m_syst_helpers_range_from\fi
+   \ifempty\m_syst_helpers_range_to\let\m_syst_helpers_range_to\m_syst_helpers_range_from\fi
    \dostepwiserecurse\m_syst_helpers_range_from\m_syst_helpers_range_to\plusone{\m_helpers_range_action{##1}}}%
 
 \unexpanded\def\processranges[#1]#2% #1= n:m,p,q:r
@@ -6480,7 +6537,7 @@
    \fi}
 
 \def\constantemptyargument#1%
-  {\ifx#1\empty
+  {\ifempty#1%
      \noexpand\empty
    \else
      {#1}%
@@ -6588,6 +6645,6 @@
 
 \unexpanded\def\emptyargumentcondition#1%
   {\edef\m_syst_string_one{#1}%
-   \ifx\m_syst_string_one\empty}
+   \ifempty\m_syst_string_one}
 
 \protect \endinput
diff --git a/tex/context/base/mkiv/tabl-ntb.mkxl b/tex/context/base/mkiv/tabl-ntb.mkxl
index adabc3139..cc2df4c69 100644
--- a/tex/context/base/mkiv/tabl-ntb.mkxl
+++ b/tex/context/base/mkiv/tabl-ntb.mkxl
@@ -711,12 +711,12 @@
    \edef\m_tabl_ntb_n{\naturaltableparameter\c!n}%
    \edef\m_tabl_ntb_m{\naturaltableparameter\c!m}%
    %
-   \ifx\m_tabl_ntb_n\empty
+   \ifempty\m_tabl_ntb_n
      \global\advance\c_tabl_ntb_spn\c_tabl_ntb_nx\relax
    \orelse\ifnum\m_tabl_ntb_n=\c_tabl_ntb_running_col\else
      \tabl_ntb_td_pass_n{#1}%
    \fi
-   \ifx\m_tabl_ntb_m\empty \else
+   \ifempty\m_tabl_ntb_m \else
      \ifnum\m_tabl_ntb_m=\c_tabl_ntb_running_col\else
        \tabl_ntb_td_pass_m{#1}%
      \fi
@@ -1351,7 +1351,7 @@
    \ifnum\scratchcounter>\c_tabl_ntb_n_of_hdnx_lines\relax
      \ifnum\scratchcounter<\c_tabl_ntb_maximum_row\relax
        \edef\p_spaceinbetween{\naturaltablelocalparameter\c!spaceinbetween}%
-       \ifx\p_spaceinbetween\empty\else
+       \ifempty\p_spaceinbetween\else
          \blank[\p_spaceinbetween]%
        \fi
      \fi
@@ -1515,7 +1515,7 @@
    \fi
    \dp\scratchbox\zeropoint
    \edef\!!stringa{\tabl_ntb_get_ref{#1}{#2}}%
-   \ifx\!!stringa\empty
+   \ifempty\!!stringa
      \box\scratchbox
    \else
      \normalexpanded{\noexpand\directgotobox{\box\scratchbox}[\!!stringa]}% to be checked
@@ -1534,7 +1534,7 @@
       % nothing
    \orelse\ifx\localwidth\v!broad
       % nothing
-   \orelse\ifx\localwidth\empty
+   \orelse\ifempty\localwidth
       % nothing (safeguard)
    \else
      \tabl_ntb_cell_finalize_indeed
@@ -1729,7 +1729,7 @@
         \setbox\tsplitnext\vbox{\unvcopy\tsplitnext\unvcopy\scratchbox}}% \vpack ?
    \fi
    \edef\p_spaceinbetween{\naturaltablelocalparameter\c!spaceinbetween}%
-   \ifx\p_spaceinbetween\empty\else
+   \ifempty\p_spaceinbetween\else
      \blank[\p_spaceinbetween]%
    \fi
    \def\postprocesstsplit{\postprocessTABLEsplitbox{\box\tsplitresult}}%
@@ -2057,7 +2057,7 @@
       \fi
       \ifcase\c_anch_backgrounds_text_count\else
         \edef\p_region{\naturaltablelocalparameter\c!region}%
-        \ifx\p_region\empty\ifnum\tabl_ntb_get_bck{#1}{#2}>\zerocount
+        \ifempty\p_region\ifnum\tabl_ntb_get_bck{#1}{#2}>\zerocount
           \letnaturaltablelocalparameter\c!region\v!yes
         \fi\fi
       \fi
diff --git a/tex/context/base/mkiv/tabl-tbl.mkxl b/tex/context/base/mkiv/tabl-tbl.mkxl
index dc8ae0214..3a1d835ea 100644
--- a/tex/context/base/mkiv/tabl-tbl.mkxl
+++ b/tex/context/base/mkiv/tabl-tbl.mkxl
@@ -297,7 +297,9 @@
 % 1 = RC column raw    RQ equal column raw
 % 2 = HC column hook   HQ equal column hook
 
-% handy helper
+% handy helper (problem: we have an extra group when we nest; playing with en engine
+% solution turned out to be too messy due to states; an ignoreendgroup trick also is
+% messy and interferes).
 
 \def\tabulatenoalign % public ?
   {\noalign
@@ -364,7 +366,7 @@
 
 \unexpanded\def\tabl_tabulate_check_local_color_second#1#2%
   {\relax
-   \ifx\m_tabl_tabulate_color_local\empty
+   \ifempty\m_tabl_tabulate_color_local
      \xdef\m_tabl_tabulate_color{#1}%
    \else
      \glet\m_tabl_tabulate_color\m_tabl_tabulate_color_local
@@ -391,7 +393,7 @@
 
 \unexpanded\def\tabl_tabulate_check_local_vrule_color_second#1%
   {\relax
-   \ifx\m_tabl_tabulate_vrule_color_local\empty
+   \ifempty\m_tabl_tabulate_vrule_color_local
      \xdef\m_tabl_tabulate_vrule_color{#1}%
    \else
      \glet\m_tabl_tabulate_vrule_color\m_tabl_tabulate_vrule_color_local
@@ -475,7 +477,7 @@
             \bgroup % we cannot combine the if because a cell may have only one ##
                 \tabl_tabulate_hook_b
                 \c_tabl_tabulate_align\constantnumber\c_tabl_tabulate_align % needed in tag passing
-                \ifx\m_tabl_tabulate_alignment\empty \else
+                \ifempty\m_tabl_tabulate_alignment \else
                     \spac_align_use_now{\m_tabl_tabulate_alignment}%
                 \fi
                 \noexpand\dostarttagged\noexpand\t!tabulatecell\noexpand\empty
@@ -490,7 +492,7 @@
                     \the\t_tabl_tabulate_font
                     \the\t_tabl_tabulate_settings
                     \the\t_tabl_tabulate_before
-                    \ifx\m_tabl_tabulate_text_color\empty
+                    \ifempty\m_tabl_tabulate_text_color
                         \expandafter\gobbleoneargument
                     \else
                         \expandafter\dofastcoloractivation
@@ -818,7 +820,7 @@
    \global\advance\c_tabl_tabulate_columns\plusone
    \expandafter\let\csname\??tabulatesetup\the\c_tabl_tabulate_columns\endcsname\donothing % here ?
    \edef\currenttabulationtrulespec{#1}%
-   \ifx\currenttabulationtrulespec\empty
+   \ifempty\currenttabulationtrulespec
      \global\d_tabl_tabulate_vrulethickness\zeropoint
    \else
      \global\d_tabl_tabulate_vrulethickness\d_tabl_tabulate_vrulethickness_default
@@ -839,7 +841,7 @@
   {\glet\m_tabl_tabulate_color\empty
    \glet\m_tabl_tabulate_vrule_color\empty
    \edef\currenttabulationtrulespec{#1}%
-   \ifx\currenttabulationtrulespec\empty
+   \ifempty\currenttabulationtrulespec
      \global\d_tabl_tabulate_vrulethickness\zeropoint
    \else
      \global\d_tabl_tabulate_vrulethickness\d_tabl_tabulate_vrulethickness_default
@@ -1099,8 +1101,8 @@
 
 \def\tabl_tabulate_check_full_content % - needed, else confusion with \c!header
   {\ifcsname\??tabulatehead\currenttabulation\endcsname
-    %\expandafter\ifx\csname\??tabulatehead\currenttabulation\endcsname\empty
-     \expandafter\ifx\lastnamedcs\empty
+    %\expandafter\ifempty\csname\??tabulatehead\currenttabulation\endcsname
+     \expandafter\ifempty\lastnamedcs
        \let\tabl_tabulate_insert_head\empty
      \else
        \let\tabl_tabulate_insert_head\tabl_tabulate_insert_head_content
@@ -1109,8 +1111,8 @@
      \let\tabl_tabulate_insert_head\empty
    \fi
    \ifcsname\??tabulatefoot\currenttabulation\endcsname
-     \expandafter\ifx\csname\??tabulatefoot\currenttabulation\endcsname\empty
-    %\expandafter\ifx\lastnamedcs\empty
+     \expandafter\ifempty\csname\??tabulatefoot\currenttabulation\endcsname
+    %\expandafter\ifempty\lastnamedcs
        \let\tabl_tabulate_insert_foot\empty
      \else
        \let\tabl_tabulate_insert_foot\tabl_tabulate_insert_foot_content
@@ -1213,7 +1215,7 @@
      \setupcurrenttabulation[#1]%
    \else
      \def\p_format{#1}%
-     \ifx\p_format\empty
+     \ifempty\p_format
        \def\p_format{|l|p|}%
      \fi
      \lettabulationparameter\c!format\p_format
@@ -1222,7 +1224,7 @@
 
 \def\tabl_start_regular_two[#1][#2]%
   {\def\p_format{#1}%
-   \ifx\p_format\empty
+   \ifempty\p_format
      \let\p_format\tabl_default_format
    \fi
    \lettabulationparameter\c!format\p_format
@@ -1368,7 +1370,7 @@
    \let\m_tabl_tabulate_hrule_color_default\p_rulecolor
    \d_tabl_tabulate_vrulethickness_default\p_rulethickness
    \d_tabl_tabulate_hrulethickness_default\p_rulethickness
-   \ifx\p_bodyfont\empty\else
+   \ifempty\p_bodyfont\else
      \switchtobodyfont[\p_bodyfont]%
    \fi
    \postponenotes % new, to be tested / will be configurable
@@ -1379,7 +1381,7 @@
    \d_tabl_tabulate_indent\dimexpr\leftskip+\hangindent\ifx\p_indenting\v!yes+\parindent\fi\relax
    \global\c_tabl_tabulate_column\zerocount
    \processcontent
-     {\ifconditional\c_tabl_generic stoptabulate\else\e!stop\ifx\currenttabulationparent\empty\v!tabulate\else\currenttabulationparent\fi\fi}
+     {\ifconditional\c_tabl_generic stoptabulate\else\e!stop\ifempty\currenttabulationparent\v!tabulate\else\currenttabulationparent\fi\fi}
      \tabl_tabulate_insert_body
      \tabl_tabulate_process}
 
@@ -1421,13 +1423,13 @@
 \to \t_tabl_tabulate_every_row
 
 \unexpanded\def\tabl_tabulate_color_side_right_second
-  {\ifx\m_tabl_tabulate_color_previous\empty \else
+  {\ifempty\m_tabl_tabulate_color_previous \else
      \tabl_tabulate_color_set\m_tabl_tabulate_color_previous
      \glet\m_tabl_tabulate_color_previous\empty
    \fi}
 
 \unexpanded\def\tabl_tabulate_color_side_left_second
-  {\ifx\m_tabl_tabulate_color\empty \else
+  {\ifempty\m_tabl_tabulate_color \else
      \ifcase\c_tabl_tabulate_colorspan
      \or
        \tabl_tabulate_color_set\m_tabl_tabulate_color
@@ -1437,7 +1439,7 @@
    \fi}
 
 \unexpanded\def\tabl_tabulate_color_side_both_second
-  {\ifx\m_tabl_tabulate_color\empty \else
+  {\ifempty\m_tabl_tabulate_color \else
      \tabl_tabulate_color_set\m_tabl_tabulate_color
      \ifcase\c_tabl_tabulate_colorspan
        %\glet\m_tabl_tabulate_color_previous\empty
@@ -1572,7 +1574,7 @@
 
 \unexpanded\def\tabl_tabulate_column_vrule_inject_second
   {\ifcase\d_tabl_tabulate_vrulethickness\else
-     \ifx\m_tabl_tabulate_vrule_color\empty
+     \ifempty\m_tabl_tabulate_vrule_color
        \tabl_tabulate_column_vruled_normal
      \else
        \tabl_tabulate_column_vruled_colored
@@ -1622,7 +1624,7 @@
 \def\tabl_tabulate_column_rule_separator_inject % can be sped up (will do when used frequently)
   {\bgroup
    \s_tabl_tabulate_separator\strutdp
-   \ifx\p_distance\empty\else
+   \ifempty\p_distance\else
      \let\m_tabl_tabulate_separator_factor\plusone
      \processcommacommand[\p_distance]\tabl_tabulate_column_rule_separator_step
      \s_tabl_tabulate_separator\m_tabl_tabulate_separator_factor\s_tabl_tabulate_separator
@@ -1671,7 +1673,7 @@
 
 \unexpanded\def\tabl_tabulate_hrule_inject_second
   {\ifcase\d_tabl_tabulate_hrulethickness_local\else
-     \ifx\currenttabulationlocalhrulecolor\empty
+     \ifempty\currenttabulationlocalhrulecolor
        \tabl_tabulate_hrule_inject_normal
      \else
        \tabl_tabulate_hrule_inject_colored
@@ -2005,7 +2007,7 @@
 
 \unexpanded\def\tabl_tabulate_bbskip_second_split_yes
   {\ifvoid\b_tabl_tabulate_current\c_tabl_tabulate_column
-     \ifx\tabl_tabulate_flush_collected_indeed\empty\else
+     \ifempty\tabl_tabulate_flush_collected_indeed\else
        \setbox0\hbox
      \fi
   \fi}
@@ -2501,7 +2503,7 @@
 \def\tabl_tabulate_TB_indeed[#1]%
   {\iffirstargument
      \blank[#1]
-   \orelse\ifx\m_tabl_tabulate_blank_default\empty
+   \orelse\ifempty\m_tabl_tabulate_blank_default
      \blank
    \else
      \blank[\m_tabl_tabulate_blank_default]%
@@ -2820,8 +2822,8 @@
 
 \unexpanded\def\tabl_synchronize_row_background
   {\iftrialtypesetting\else
-     \ifx\m_table_current_row_background_filler\empty
-       \ifx\m_table_current_row_background\empty
+     \ifempty\m_table_current_row_background_filler
+       \ifempty\m_table_current_row_background
          % nothing
          \tabl_synchronize_row_background_dummy
        \else
@@ -2952,8 +2954,8 @@
 \unexpanded\def\tabl_tabulate_BC_first % overloaded
   {\tabl_tabulate_column_normal\plusone\zerocount
    \let\fontstyle\globalfontstyle
-   \ifx\m_table_current_row_background\empty
-     \ifx\m_table_current_row_background_filler\empty
+   \ifempty\m_table_current_row_background
+     \ifempty\m_table_current_row_background_filler
        \usetabulationstyleandcolor\c!headstyle\c!headcolor
      \else
        \usetabulationstyleandcolor\c!foregroundstyle\c!foregroundcolor
@@ -2965,11 +2967,11 @@
 \unexpanded\def\tabl_tabulate_A_first
   {\global\advance\c_tabl_tabulate_autocolor\plusone
    \edef\m_table_current_row_background_auto{\tabulateparameter{\c!backgroundcolor:\number\c_tabl_tabulate_autocolor}}%
-   \ifx\m_table_current_row_background_auto\empty
+   \ifempty\m_table_current_row_background_auto
      \global\c_tabl_tabulate_autocolor\plusone
      \edef\m_table_current_row_background_auto{\tabulateparameter{\c!backgroundcolor:\number\c_tabl_tabulate_autocolor}}%
    \fi
-   \ifx\m_table_current_row_background_auto\empty
+   \ifempty\m_table_current_row_background_auto
      \let\m_table_current_row_background_auto\empty % \m_table_current_row_background_default
    \fi
    \tabl_register_row_background{\m_table_current_row_background_auto}}
diff --git a/tex/context/base/mkiv/type-ini.mklx b/tex/context/base/mkiv/type-ini.mklx
index 5470c9016..b4eee64d8 100644
--- a/tex/context/base/mkiv/type-ini.mklx
+++ b/tex/context/base/mkiv/type-ini.mklx
@@ -337,7 +337,7 @@
 \def\font_typescripts_check#asked#target#followup[#value]% script use value next
   {\donefalse
    \edef\m_font_typescripts_check{#value}%
-   \ifx\m_font_typescripts_check\empty % no longer needed / met
+   \ifempty\m_font_typescripts_check % no longer needed / met
      \ifcase\typescriptmethod\or\donetrue\fi
    \orelse\ifx#asked\s!all
      \donetrue
@@ -504,7 +504,7 @@
    \the\everybeforedefinetypeface}
 
 \def\tsvar#key#default% undocumented and unofficial
-  {\expandafter\ifx\csname\??ts#key\endcsname\empty
+  {\expandafter\ifempty\csname\??ts#key\endcsname
      #default%
    \else
      \csname\??ts#key\endcsname
@@ -532,7 +532,7 @@
    \let\globalfontclass\fontclass
    \ifsecondargument
      \setupbodyfont[#settings]%
-   \orelse\ifx\fontclass\empty
+   \orelse\ifempty\fontclass
      \setupbodyfont[\s!rm]%
    \orelse\ifcsname\??typescriptdefaultstyles\fontclass\endcsname
     %\setupbodyfont[\csname\??typescriptdefaultstyles\fontclass\endcsname]%
@@ -547,7 +547,7 @@
    \let\globalfontclass\globalfontclass
    \ifsecondargument
      \switchtobodyfont[#settings]%
-   \orelse\ifx\fontclass\empty
+   \orelse\ifempty\fontclass
      \switchtobodyfont[\s!rm]%
    \orelse\ifcsname\??typescriptdefaultstyles\fontclass\endcsname
     %\switchtobodyfont[\csname\??typescriptdefaultstyles\fontclass\endcsname]%
@@ -606,7 +606,7 @@
                                                                               \s!Serif \fi\fi\fi}
 
 \unexpanded\def\font_helpers_set_fontstyle_of_fontclass
-  {\ifx\fontclass\empty
+  {\ifempty\fontclass
      \let\fontstyle\s!rm
    \orelse\ifcsname\??typescriptdefaultstyles\fontclass\endcsname
     %\edef\fontstyle{\csname\??typescriptdefaultstyles\fontclass\endcsname}%
diff --git a/tex/context/modules/mkiv/m-visual.mkiv b/tex/context/modules/mkiv/m-visual.mkiv
index 6ec0a52b0..a7cecef93 100644
--- a/tex/context/modules/mkiv/m-visual.mkiv
+++ b/tex/context/modules/mkiv/m-visual.mkiv
@@ -56,9 +56,7 @@
 \unexpanded\def\fakelines#1#2% min max / 3 10
   {\fakeparindent
    \scratchdimen\hsize
-   \ifindentation
-     \advance\scratchdimen -\parindent
-   \fi
+   \advance\scratchdimen -\parindent
    \fakerule\scratchdimen\break
    \getrandomcount\scratchcounter{\ifcase0#1 3\else#1\fi}{\ifcase0#2 10\else#2\fi}%
    \dorecurse\scratchcounter{\fakerule\hsize}%
@@ -128,7 +126,7 @@
 
 \unexpanded\def\fakeparindent
   {\noindent
-   \ifindentation
+   \ifzeropt\parindent\else
      \ifx\dofakedroppedcaps\relax
        {\fakeparindentcolor
         \vrule
diff --git a/tex/generic/context/luatex/luatex-fonts-merged.lua b/tex/generic/context/luatex/luatex-fonts-merged.lua
index 6c07e67f2..eec0c0a5b 100644
--- a/tex/generic/context/luatex/luatex-fonts-merged.lua
+++ b/tex/generic/context/luatex/luatex-fonts-merged.lua
@@ -1,6 +1,6 @@
 -- merged file : c:/data/develop/context/sources/luatex-fonts-merged.lua
 -- parent file : c:/data/develop/context/sources/luatex-fonts.lua
--- merge date  : 2020-05-12 16:17
+-- merge date  : 2020-05-18 16:46
 
 do -- begin closure to overcome local limits and interference