2020-10-30 22:27:00

1 files changed, 254 insertions, 417 deletions

diff --git a/tex/context/base/mkiv/mult-aux.mkxl b/tex/context/base/mkiv/mult-aux.mkxl
index 1df5bcf24..c1c99edbd 100644
--- a/tex/context/base/mkiv/mult-aux.mkxl
+++ b/tex/context/base/mkiv/mult-aux.mkxl
@@ -21,7 +21,7 @@
 
 \unprotect
 
-\edef\??empty{\Uchar25}  \letvalue{\Uchar25}\empty % hex 19
+\immutable\edef\??empty{\Uchar25}  \immutable\letvalue{\Uchar25}\empty % hex 19
 
 % \edef\s!parent{\Uchar29} % inlining  is ugly, a tiny bit faster, but neglectable on a run
 
@@ -174,26 +174,17 @@
 
 \let\m_mult_interfaces_namespace\empty
 
-\def\mult_interfaces_get_parameters#1[#2%
-  {\if\noexpand#2]%
-     \expandafter\gobbleoneargument
-   \else
-     \def\m_mult_interfaces_namespace{#1}%
-     \expandafter\mult_interfaces_get_parameters_indeed
-   \fi#2}
+\def\mult_interfaces_get_parameters#1[%
+  {\def\m_mult_interfaces_namespace{#1}%
+   \futureexpandis]\gobbleoneargument\mult_interfaces_get_parameters_indeed}
 
-\def\mult_interfaces_get_parameters_indeed#1]% namespace already set
+\def\mult_interfaces_get_parameters_indeed#1]%
   {\mult_interfaces_get_parameters_item#1\ignorearguments\ignorearguments}
 
-\def\mult_interfaces_get_parameters_item_next
-  {\expandafterspaces\mult_interfaces_get_parameters_item}
-
-\def\mult_interfaces_get_parameters_item#1,%
-  {\ifarguments
-     % done
-   \else
+\def\mult_interfaces_get_parameters_item#*#1,%
+  {\ifarguments \else
      \mult_interfaces_get_parameters_item_okay#1,\ignorearguments
-     \expandafter\mult_interfaces_get_parameters_item_next
+     \expandafter\mult_interfaces_get_parameters_item
    \fi}
 
 \def\mult_interfaces_get_parameters_item_okay#1=#2,%
@@ -219,25 +210,16 @@
        \or
          \mult_interfaces_get_parameters_item_error
        \else
-         \expandafter\def\csname\m_mult_interfaces_namespace#1\endcsname{#2}%
+         \defcsname\m_mult_interfaces_namespace#1\endcsname{#2}%
        \fi}
 
-%     \def\mult_interfaces_get_parameters_item_error#0\csname#2#3\endcsname#0%
-%       {\if,#3\else\mult_interfaces_get_parameters_error_indeed{#2}{#3}\fi}
-
-    \def\mult_interfaces_get_parameters_item_error#-\csname#1#2\endcsname#-%
+    \def\mult_interfaces_get_parameters_item_error#-\defcsname#1#2\endcsname#-%
       {\if,#2\else\mult_interfaces_get_parameters_error_indeed{#1}{#2}\fi}
 
 \stopinterface
 
 %D Used?
 
-% \def\mult_check_for_assignment_indeed#0=#2#0^^^^0004%
-%   {\if#2^^^^0003\assignmentfalse\else\assignmenttrue\fi}
-%
-% \def\mult_check_for_assignment_indeed_begin_#0=#2#0^^^^0004%
-%   {\if#2^^^^0003}
-
 \def\mult_check_for_assignment_indeed#-=#1#-^^^^0004%
   {\if#1^^^^0003\assignmentfalse\else\assignmenttrue\fi}
 
@@ -258,20 +240,13 @@
 %D and that only the high level setup commands are used with language specific
 %D interfaces.
 
-% \protected\def\mult_interfaces_let #1#2{\expandafter\let \csname#1\ifcsname\k!prefix!#2\endcsname\csname\k!prefix!#2\endcsname\else#2\fi\endcsname}
-% \protected\def\mult_interfaces_lete#1#2{\expandafter\let \csname#1\ifcsname\k!prefix!#2\endcsname\csname\k!prefix!#2\endcsname\else#2\fi\endcsname\empty}
-% \protected\def\mult_interfaces_def #1#2{\expandafter\def \csname#1\ifcsname\k!prefix!#2\endcsname\csname\k!prefix!#2\endcsname\else#2\fi\endcsname}
-% \protected\def\mult_interfaces_edef#1#2{\expandafter\edef\csname#1\ifcsname\k!prefix!#2\endcsname\csname\k!prefix!#2\endcsname\else#2\fi\endcsname}
-% \protected\def\mult_interfaces_gdef#1#2{\expandafter\gdef\csname#1\ifcsname\k!prefix!#2\endcsname\csname\k!prefix!#2\endcsname\else#2\fi\endcsname}
-% \protected\def\mult_interfaces_xdef#1#2{\expandafter\xdef\csname#1\ifcsname\k!prefix!#2\endcsname\csname\k!prefix!#2\endcsname\else#2\fi\endcsname}
-
 % \startinterface english
-    \protected\def\mult_interfaces_let #1#2{\expandafter \let\csname#1#2\endcsname}
-    \protected\def\mult_interfaces_lete#1#2{\expandafter \let\csname#1#2\endcsname\empty}
-    \protected\def\mult_interfaces_def #1#2{\expandafter \def\csname#1#2\endcsname}
-    \protected\def\mult_interfaces_edef#1#2{\expandafter\edef\csname#1#2\endcsname}
-    \protected\def\mult_interfaces_gdef#1#2{\expandafter\gdef\csname#1#2\endcsname}
-    \protected\def\mult_interfaces_xdef#1#2{\expandafter\xdef\csname#1#2\endcsname}
+    \protected\def\mult_interfaces_let #1#2{\letcsname#1#2\endcsname}
+    \protected\def\mult_interfaces_lete#1#2{\letcsname#1#2\endcsname\empty}
+    \protected\def\mult_interfaces_def #1#2{\defcsname#1#2\endcsname}
+    \protected\def\mult_interfaces_edef#1#2{\edefcsname#1#2\endcsname}
+    \protected\def\mult_interfaces_gdef#1#2{\globaldef\csname#1#2\endcsname}
+    \protected\def\mult_interfaces_xdef#1#2{\globaledef\csname#1#2\endcsname}
 % \stopinterface
 
 %D Do, we only interface the assignment definition:
@@ -279,7 +254,7 @@
 \protected\def\mult_interfaces_adef#1#2{\expandafter\def \csname#1\ifcsname\k!prefix!#2\endcsname\csname\k!prefix!#2\endcsname\else#2\fi\endcsname}
 
 \startinterface english
-    \protected\def\mult_interfaces_adef#1#2{\expandafter \def\csname#1#2\endcsname}
+    \protected\def\mult_interfaces_adef#1#2{\defcsname#1#2\endcsname}
 \stopinterface
 
 % the commented detokenized variant that backtracks ... needs testing usage first
@@ -299,19 +274,17 @@
 \def\mult_interfaces_detokenize{\expandafter\expandafter\expandafter\detokenize\expandafter\expandafter\expandafter}
 
 \protected\def\mult_interfaces_install_parameter_handler#1#2#3#4#5#6#7#8#9% inlining \csname*\endcsname is more efficient (#3 and #6 only)
-  {\ifx#2\relax\let#2\empty\fi                                             % it is hardly faster but produces less expansion tracing
-   \def#3##1{\csname\ifcsname#1#2:##1\endcsname#1#2:##1\else\expandafter#5\csname#1#2:\s!parent\endcsname{##1}\fi\endcsname}%
-   \def#4##1##2{\ifcsname##1:##2\endcsname##1:##2\else\expandafter#5\csname##1:\s!parent\endcsname{##2}\fi}%
-  %\def#5##1##2{\ifx##1\relax\??empty\else#4{##1}{##2}\fi}% is {} needed around ##1 ?
-  %\def#5##1##2{\ifx##1\relax\??empty\else#4##1{##2}\fi}% is {} needed around ##1 ?
-  %\def#5##1##2{\ifx##1\relax^^^^0019\else#4##1{##2}\fi}% is {} needed around ##1 ?
-   \edef#5##1##2{\noexpand\ifx##1\relax\??empty\noexpand\else\noexpand#4##1{##2}\noexpand\fi}% is {} needed around ##1 ?
-   \def#6##1##2{\csname\ifcsname#1##1:##2\endcsname#1##1:##2\else\expandafter#5\csname#1##1:\s!parent\endcsname{##2}\fi\endcsname}%
-   \def#7##1{\detokenize\expandafter\expandafter\expandafter{\csname#1#2:##1\endcsname}}% always root, no backtrack
-   \def#8##1{\begincsname#1#2:##1\endcsname}
-   \def#9##1##2{\expandafter\let\expandafter##1\csname\ifcsname#1#2:##2\endcsname#1#2:##2\else\expandafter#5\csname#1#2:\s!parent\endcsname{##2}\fi\endcsname}}
-
-\protected\def\installparameterhandler#1#2%
+  {\ifx#2\relax\let#2\empty\fi                                            % it is hardly faster but produces less expansion tracing
+   \frozen\def#3##1{\csname\ifcsname#1#2:##1\endcsname#1#2:##1\else\expandafter#5\csname#1#2:\s!parent\endcsname{##1}\fi\endcsname}%
+   \frozen\def#4##1##2{\ifcsname##1:##2\endcsname##1:##2\else\expandafter#5\csname##1:\s!parent\endcsname{##2}\fi}%
+   \frozen\edef#5##1##2{\noexpand\ifx##1\relax\??empty\noexpand\else\noexpand#4##1{##2}\noexpand\fi}% is {} needed around ##1 ?
+   \frozen\def#6##1##2{\csname\ifcsname#1##1:##2\endcsname#1##1:##2\else\expandafter#5\csname#1##1:\s!parent\endcsname{##2}\fi\endcsname}%
+   \frozen\def#7##1{\detokenize\expandafter\expandafter\expandafter{\csname#1#2:##1\endcsname}}% always root, no backtrack
+   \frozen\def#8##1{\begincsname#1#2:##1\endcsname}%
+   % TODO
+   \frozen\def#9##1##2{\expandafter\let\expandafter##1\csname\ifcsname#1#2:##2\endcsname#1#2:##2\else\expandafter#5\csname#1#2:\s!parent\endcsname{##2}\fi\endcsname}}
+
+\permanent\protected\def\installparameterhandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_parameter_handler
         {\noexpand#1}% \??aa
@@ -325,10 +298,10 @@
         \expandafter\noexpand\csname letfrom#2parameter\endcsname}} % strict#2parameter is gone
 
 \protected\def\mult_interfaces_install_root_parameter_handler#1#2#3%
-  {\def#2##1{\detokenize\expandafter\expandafter\expandafter{\csname#1:##1\endcsname}}% always root
-   \def#3##1{\begincsname#1:##1\endcsname}}
+  {\frozen\def#2##1{\detokenize\expandafter\expandafter\expandafter{\csname#1:##1\endcsname}}% always root
+   \frozen\def#3##1{\begincsname#1:##1\endcsname}}
 
-\protected\def\installrootparameterhandler#1#2%
+\permanent\protected\def\installrootparameterhandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_root_parameter_handler
         {\noexpand#1}% \??aa
@@ -337,18 +310,17 @@
 
 \protected\def\mult_interfaces_install_parameter_hash_handler#1#2#3#4#5#6#7#8#9%
   {\ifx#2\relax\let#2\empty\fi
-   \def#3##1{#1#4{#1#2}{##1}:}% leading #1 was missing .. is this one used?
-   \def#4##1##2{\ifcsname##1:##2\endcsname##1\else\expandafter#5\csname##1:\s!parent\endcsname{##2}\fi}%
-  %\def#5##1##2{\ifx##1\relax\else#4{##1}{##2}\fi}%
-   \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{\ifempty#2\orelse\ifcsname#1#2:\s!parent\endcsname\else\expandafter\let\csname#1#2:\s!parent\endcsname#1\fi}%
-   \protected\def#9##1{\expandafter\edef\csname#1##1:\s!parent\endcsname{#1#2}}}
-
-\protected\def\installparameterhashhandler#1#2%
-  {\expandafter\let\csname#2namespace\endcsname#1%
+   \frozen\def#3##1{#1#4{#1#2}{##1}:}% leading #1 was missing .. is this one used?
+   \frozen\def#4##1##2{\ifcsname##1:##2\endcsname##1\else\expandafter#5\csname##1:\s!parent\endcsname{##2}\fi}%
+   \frozen\def#5##1##2{\ifx##1\relax\else#4##1{##2}\fi}%
+   \frozen\def#6{#1#2:}%
+   \frozen\def#7##1{#1##1:}%
+   \frozen\def#8{\ifempty#2\orelse\ifcsname#1#2:\s!parent\endcsname\else\letcsname#1#2:\s!parent\endcsname#1\fi}%
+   \frozen\protected\def#9##1{\edefcsname#1##1:\s!parent\endcsname{#1#2}}}
+
+\permanent\protected\def\installparameterhashhandler#1#2%
+%   {\expandafter\let\csname#2namespace\endcsname#1%
+  {\letcsname#2namespace\endcsname#1%
    \normalexpanded
      {\mult_interfaces_install_parameter_hash_handler
         {\noexpand#1}% \??aa
@@ -365,23 +337,16 @@
 
 % todo: inline the def/let
 
-% \protected\def\mult_interfaces_install_parameter_set_handler#1#2#3#4#5#6%
-%   {\ifx#2\relax\let#2\empty\fi
-%    \protected\def#3{\mult_interfaces_def {#1#2:}}%  ##1 {##2} (braces are mandate)
-%    \protected\def#4{\mult_interfaces_edef{#1#2:}}%  ##1 {##2} (braces are mandate)
-%    \protected\def#5{\mult_interfaces_let {#1#2:}}%  ##1 ##2
-%    \protected\def#6{\mult_interfaces_lete{#1#2:}}}% ##1
-%
 % \startinterface english
     \protected\def\mult_interfaces_install_parameter_set_handler#1#2#3#4#5#6%
       {\ifx#2\relax\let#2\empty\fi
-       \protected\def#3##1{\expandafter \def\csname#1#2:##1\endcsname}%        ##1 {##2} (braces are mandate)
-       \protected\def#4##1{\expandafter\edef\csname#1#2:##1\endcsname}%        ##1 {##2} (braces are mandate)
-       \protected\def#5##1{\expandafter \let\csname#1#2:##1\endcsname}%        ##1 ##2
-       \protected\def#6##1{\expandafter \let\csname#1#2:##1\endcsname\empty}}% ##1
+       \frozen\protected\def#3##1{\defcsname#1#2:##1\endcsname}%        ##1 {##2} (braces are mandate)
+       \frozen\protected\def#4##1{\edefcsname#1#2:##1\endcsname}%        ##1 {##2} (braces are mandate)
+       \frozen\protected\def#5##1{\letcsname#1#2:##1\endcsname}%        ##1 ##2
+       \frozen\protected\def#6##1{\letcsname#1#2:##1\endcsname\empty}}% ##1
 % \stopinterface
 
-\protected\def\installparametersethandler#1#2%
+\permanent\protected\def\installparametersethandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_parameter_set_handler
         {\noexpand#1}% \??aa
@@ -398,23 +363,19 @@
 \let\currentcolorparameter\empty
 
 \protected\def\mult_interfaces_install_style_and_color_handler#1#2#3#4%
-  {\protected\def#2##1##2% style color
+  {\frozen\protected\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
       \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}%
       \ifempty\currentcolorparameter\else\dousecurrentcolorparameter\fi}%
-   \protected\def#3##1% style
+   \frozen\protected\def#3##1% style
      {\edef\currentstyleparameter{#1{##1}}% this name is public
-     %\ifx\currentstyleparameter\empty\else\dousecurrentstyleparameter\fi}%
       \ifempty\currentstyleparameter\else\dousecurrentstyleparameter\fi}%
-   \protected\def#4##1% color
+   \frozen\protected\def#4##1% color
      {\edef\currentcolorparameter{#1{##1}}% this name is public
-     %\ifx\currentcolorparameter\empty\else\dousecurrentcolorparameter\fi}}%
       \ifempty\currentcolorparameter\else\dousecurrentcolorparameter\fi}}
 
-\protected\def\installstyleandcolorhandler#1#2%
+\permanent\protected\def\installstyleandcolorhandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_style_and_color_handler
         \expandafter\noexpand\csname #2parameter\endcsname
@@ -424,123 +385,107 @@
 
 \let\definehandlerparent\empty
 
-% \def\mult_check_for_parent#1#2#3#4%
-%   {\ifcsname#1#4:\s!parent\endcsname \else \ifx#4\empty \else
-%      \writestatus\m!system{error: invalid parent #4 for #3, #4 defined too (best check it)}%
-%      \expandafter\edef\csname#1#4:\s!parent\endcsname{#2}%
-%    \fi \fi}
-
 \def\mult_check_for_parent#1#2#3#4%
   {\ifcsname#1#4:\s!parent\endcsname\orelse\ifx#4\empty\else
      \writestatus\m!system{error: invalid parent #4 for #3, #4 defined too (best check it)}%
-     \expandafter\edef\csname#1#4:\s!parent\endcsname{#2}%
+%      \expandafter\edef\csname#1#4:\s!parent\endcsname{#2}%
+     \edefcsname#1#4:\s!parent\endcsname{#2}%
    \fi}
 
-%def\mult_interfaces_chain#1#2{\ifcsname#1#2:\s!chain\endcsname\csname#1#2:\s!chain\endcsname\space\fi}
-%def\getparentchain       #1#2{\ifcsname#1#2:\s!chain\endcsname\csname#1#2:\s!chain\endcsname\fi}
-%def\getcurrentparentchain#1#2{\ifcsname#1#2:\s!chain\endcsname\csname#1#2:\s!chain\endcsname\fi}
-
 \def\mult_interfaces_chain#1#2{\ifcsname#1#2:\s!chain\endcsname\lastnamedcs\space\fi}
 \def\getparentchain       #1#2{\begincsname#1#2:\s!chain\endcsname}
 \def\getcurrentparentchain#1#2{\begincsname#1#2:\s!chain\endcsname}
 
-\protected\def\mult_interfaces_install_define_handler#1#2#3#4#5#6#7#8#9% why is \expanded still needed in clones
-  {\ifx#4\relax\let#4\empty\fi                                          % see \defineregister
-   \protected\def#2{\dotripleempty#5}%
+\protected\def\mult_interfaces_install_define_handler#1#2#3#4#5#6#7#8% why is \expanded still needed in clones
+  {\ifx#4\relax\let#4\empty\fi                                       % see \defineregister
+   \newtoks#5%
    \newtoks#6%
-   \newtoks#7%
-   \protected\def#5[##1][##2][##3]% [child][parent][settings] | [child][settings] | [child][parent] | [child]
-     {\let#9#4%
-      \edef#4{##1}%
-      \ifthirdargument
-        \the#6% predefine
-        \edef#8{##2}%
-        \mult_check_for_parent{#1}{#3}#4#8%
-        \expandafter\edef\csname#1#4:\s!chain\endcsname{\mult_interfaces_chain#1{##2}##1}%
-        \expandafter\edef\csname#1#4:\s!parent\endcsname{#1##2}%
-        \mult_interfaces_get_parameters{#1#4:}[##3]%
-      \orelse\ifsecondargument
-        \the#6% predefine
+   \frozen\tolerant\protected\def#2[##1]##*[##2]##*[##3]% [child][parent][settings] | [child][settings] | [child][parent] | [child]
+     {\let#8#4%
+      % watch out: no \edef#4{##1} before the ifarguments because #1 can have macros
+      \ifarguments
+        \let#4\empty
+        \the#5% predefine
+        \let#7\empty
+        \letcsname#1#4:\s!chain\endcsname\empty
+        \edefcsname#1#4:\s!parent\endcsname{#3}%
+      \or
+        \edef#4{##1}%
+        \the#5% predefine
+        \let#7\empty
+        \edefcsname#1#4:\s!chain\endcsname{##1}%
+        \edefcsname#1#4:\s!parent\endcsname{#3}%
+      \or
+        \edef#4{##1}%
+        \the#5% predefine
         \relax
-       %\ifcondition\expandafter\mult_check_for_assignment_indeed_begin_\detokenize{##2}=^^^^0003^^^^0003^^^^0004%
-%         \ifcondition\mult_aux_no_assignment_indeed##2\ignorearguments
-%           \edef#8{##2}%
-%           \mult_check_for_parent{#1}{#3}#4#8%
-%           \expandafter\edef\csname#1#4:\s!chain\endcsname{\mult_interfaces_chain#1{##2}##1}%
-%           \expandafter\edef\csname#1#4:\s!parent\endcsname{#1##2}%
-%         \else
-%           \let#8\empty
-%           \expandafter\edef\csname#1#4:\s!chain\endcsname{##1}%
-%           \expandafter\edef\csname#1#4:\s!parent\endcsname{#3}%
-%           \mult_interfaces_get_parameters{#1#4:}[##2]%
-%         \fi
         \ifhastok={##2}%
-          \let#8\empty
-          \expandafter\edef\csname#1#4:\s!chain\endcsname{##1}%
-          \expandafter\edef\csname#1#4:\s!parent\endcsname{#3}%
+          \let#7\empty
+          \edefcsname#1#4:\s!chain\endcsname{##1}%
+          \edefcsname#1#4:\s!parent\endcsname{#3}%
           \mult_interfaces_get_parameters{#1#4:}[##2]%
         \else
-          \edef#8{##2}%
-          \ifempty#8%
-            \expandafter\edef\csname#1#4:\s!chain\endcsname{##1}%
-            \expandafter\edef\csname#1#4:\s!parent\endcsname{#3}%
+          \edef#7{##2}%
+          \ifempty#7%
+            \edefcsname#1#4:\s!chain\endcsname{##1}%
+            \edefcsname#1#4:\s!parent\endcsname{#3}%
           \else
-            \mult_check_for_parent{#1}{#3}#4#8%
-            \expandafter\edef\csname#1#4:\s!chain\endcsname{\mult_interfaces_chain#1{##2}##1}%
-            \expandafter\edef\csname#1#4:\s!parent\endcsname{#1##2}%
+            \mult_check_for_parent{#1}{#3}#4#7%
+            \edefcsname#1#4:\s!chain\endcsname{\mult_interfaces_chain#1{##2}##1}%
+            \edefcsname#1#4:\s!parent\endcsname{#1##2}%
           \fi
         \fi
-      \else
-        \the#6% predefine
-        \let#8\empty
-        \expandafter\edef\csname#1#4:\s!chain\endcsname{##1}%
-        \expandafter\edef\csname#1#4:\s!parent\endcsname{#3}%
+      \or
+        \edef#4{##1}%
+        \the#5% predefine
+        \edef#7{##2}%
+        \mult_check_for_parent{#1}{#3}#4#7%
+        \edefcsname#1#4:\s!chain\endcsname{\mult_interfaces_chain#1{##2}##1}%
+        \edefcsname#1#4:\s!parent\endcsname{#1##2}%
+        \mult_interfaces_get_parameters{#1#4:}[##3]%
       \fi
-      \the#7%
-      \let#4#9}}
+      \the#6%
+      \let#4#8}}
 
-\protected\def\installdefinehandler#1#2#3%
+\permanent\protected\def\installdefinehandler#1#2#3%
   {\normalexpanded
      {\mult_interfaces_install_define_handler
         {\noexpand#1}% \??aa
         \expandafter\noexpand\csname define#2\endcsname
         {\noexpand#3}% root
         \expandafter\noexpand\csname current#2\endcsname
-        \expandafter\noexpand\csname define_#2\endcsname % semi-public
         \expandafter\noexpand\csname everypreset#2\endcsname
         \expandafter\noexpand\csname everydefine#2\endcsname
         \expandafter\noexpand\csname current#2parent\endcsname
         \expandafter\noexpand\csname saved_defined_#2\endcsname}}
 
-\protected\def\mult_interfaces_install_setup_handler#1#2#3#4#5#6#7#8#9%
+\protected\def\mult_interfaces_install_setup_handler#1#2#3#4#5#6#7#8%
   {\ifx#3\relax\let#3\empty\fi
-   \protected\def#2{\dodoubleempty#4}%
-   \protected\def#6{\mult_interfaces_get_parameters{#1#3:}}% no every ! don't change it
-   \newtoks#5%
-   \newtoks#8%
-   \protected\def#4[##1][##2]% maybe helper
-     {\let#7#3%
-      \ifsecondargument
-        \def#9####1% we will have a simple one as well
+   \protected\def#5{\mult_interfaces_get_parameters{#1#3:}}% no every ! don't change it
+   \newtoks#4%
+   \newtoks#7%
+   \frozen\tolerant\protected\def#2[##1]##*[##2]% maybe helper
+     {\let#6#3%
+      \ifnum\lastarguments=\plustwo
+        \def#8####1% we will have a simple one as well
           {\edef#3{####1}%
            \mult_interfaces_get_parameters{#1#3:}[##2]%
-           \the#5}%
-        \processcommalist[##1]#9%
+           \the#4}%
+        \processcommalist[##1]#8%
       \else
         \let#3\empty
         \mult_interfaces_get_parameters{#1:}[##1]%
-        \the#5%
+        \the#4%
       \fi
-      \let#3#7%
-      \the#8}}
+      \let#3#6%
+      \the#7}}
 
-\protected\def\installsetuphandler#1#2%
+\permanent\protected\def\installsetuphandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_setup_handler
         {\noexpand#1}% \??aa
         \expandafter\noexpand\csname setup#2\endcsname
         \expandafter\noexpand\csname current#2\endcsname
-        \expandafter\noexpand\csname setup_#2\endcsname % semi-public
         \expandafter\noexpand\csname everysetup#2\endcsname
         \expandafter\noexpand\csname setupcurrent#2\endcsname
         \expandafter\noexpand\csname saved_setup_current#2\endcsname
@@ -552,10 +497,9 @@
 \let\doingrootsetnamed  \plusthree  % \setuplayout[name]
 \let\doingrootsetroot   \plusfour   % \setuplayout
 
-\protected\def\mult_interfaces_install_switch_setup_handler_a#1#2#3#4#5%
-  {\ifx#3\relax\let#3\empty\fi
-   \protected\def#2{\dodoubleempty#4}%
-   \protected\def#5{\mult_interfaces_get_parameters{#1#3:}}}
+\protected\def\mult_interfaces_install_switch_setup_handler_a#1#2#3%
+  {\ifx#2\relax\let#2\empty\fi
+   \frozen\protected\def#3{\mult_interfaces_get_parameters{#1#2:}}}
 
 \protected\def\mult_interfaces_install_switch_setup_handler_b#1#2#3#4#5#6#7#8#9%
   {\newtoks#5%
@@ -563,37 +507,15 @@
    \newtoks#8%
    \newtoks#9%
    \ifx#6\relax\let#6\empty\fi
-   \protected\def#4[##1][##2]% maybe helper
-     {\ifsecondargument % no commalist here
-        % \setuplayout[whatever][key=value]
-        \let#7#3%
-        \let#6#3%
-        \edef#3{##1}%
-        #2\doingrootsetupnamed
-        \mult_interfaces_get_parameters{#1#3:}[##2]%
+   \frozen\tolerant\protected\def#4[##1]##*[##2]% maybe helper
+     {\ifarguments
+        % \setuplayout
+        \let#6#3%      % previous becomes current
+        \let#3\empty   % current becomes empty
+        #2\doingrootsetroot
         \the#5%
-        \ifx#3#6\the#8\fi % only switchsetups if previous == current
-        \let#3#7%
-      \orelse\iffirstargument
-        %\ifcondition\expandafter\mult_check_for_assignment_indeed_begin_\detokenize{##1}=^^^^0003^^^^0003^^^^0004%
-%         \ifcondition\mult_aux_no_assignment_indeed##1\ignorearguments
-%           % \setuplayout[whatever]
-%           \let#6#3%   % previous becomes current
-%           \edef#3{##1}% this will catch reset so one needs to test for it
-%           #2\doingrootsetnamed
-%           \the#5%     % we can check for previous vs current
-%           \the#8% switchsetups
-%         \else
-%           % \setuplayout[key=value]
-%           \let#7#3%
-%           \let#6#3%
-%           \let#3\empty
-%           #2\doingrootsetuproot
-%           \mult_interfaces_get_parameters{#1:}[##1]%
-%           \the#5%
-%           \the#8% switchsetups
-%           \let#3#7%
-%         \fi
+        \the#8% switchsetups
+      \or
         \ifhastok={##1}%
           % \setuplayout[key=value]
           \let#7#3%
@@ -620,111 +542,113 @@
             \the#8% switchsetups
           \fi
         \fi
-      \else
-        % \setuplayout
-        \let#6#3%      % previous becomes current
-        \let#3\empty   % current becomes empty
-        #2\doingrootsetroot
+      \or
+        % \setuplayout[whatever][key=value]
+        \let#7#3%
+        \let#6#3%
+        \edef#3{##1}%
+        #2\doingrootsetupnamed
+        \mult_interfaces_get_parameters{#1#3:}[##2]%
         \the#5%
-        \the#8% switchsetups
+        \ifx#3#6\the#8\fi % only switchsetups if previous == current
+        \let#3#7%
       \fi
       #2\zerocount % mode is always zero at the end
       \the#9}}
 
-\protected\def\installswitchsetuphandler#1#2%
+\permanent\protected\def\installswitchsetuphandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_switch_setup_handler_a
         {\noexpand#1}% \??aa
-        \expandafter\noexpand\csname setup#2\endcsname
         \expandafter\noexpand\csname current#2\endcsname
-        \expandafter\noexpand\csname setup_#2\endcsname % semi-public
         \expandafter\noexpand\csname setupcurrent#2\endcsname
       \mult_interfaces_install_switch_setup_handler_b
         {\noexpand#1}% \??aa
         \expandafter\noexpand\csname #2setupmode\endcsname
         \expandafter\noexpand\csname current#2\endcsname
-        \expandafter\noexpand\csname setup_#2\endcsname % semi-public
+        \expandafter\noexpand\csname setup#2\endcsname
         \expandafter\noexpand\csname everysetup#2\endcsname
         \expandafter\noexpand\csname previous#2\endcsname
         \expandafter\noexpand\csname saved_setup_current#2\endcsname
         \expandafter\noexpand\csname everyswitch#2\endcsname
         \expandafter\noexpand\csname everysetup#2root\endcsname}}
 
-\protected\def\mult_interfaces_install_auto_setup_handler#1#2#3#4#5#6#7#8#9%
+\protected\def\mult_interfaces_install_auto_setup_handler#1#2#3#4#5#6#7#8%
   {\ifx#3\relax\let#3\empty\fi
-   \protected\def#2{\dotripleempty#4}%
-   \protected\def#6{\mult_interfaces_get_parameters{#1#3:}}%
-   \newtoks#5%
-   \def#4[##1][##2][##3]%
-     {\let#8#3%
-      \ifthirdargument
-        \def#9####1%
-          {\edef#3{####1}%
-           \expandafter\def\csname#1#3:\s!parent\endcsname{#1##2}%
-           \mult_interfaces_get_parameters{#1#3:}[##3]% always sets parent
-           \the#5}%
-        \processcommalist[##1]#9%
-      \orelse\ifsecondargument
-        \def#9####1%
-          {\edef#3{####1}%
-           #7% checks parent and sets if needed
-           \mult_interfaces_get_parameters{#1#3:}[##2]%
-           \the#5}%
-        \processcommalist[##1]#9%
-      \else
+   \frozen\protected\def#5{\mult_interfaces_get_parameters{#1#3:}}%
+   \newtoks#4%
+   \frozen\tolerant\protected\def#2[##1]##*[##2]##*[##3]%
+     {\let#7#3%
+      \ifarguments
         \let#3\empty
-        \mult_interfaces_get_parameters{#1:}[##1]%
         \the#5%
+      \or
+        \let#3\empty
+        \mult_interfaces_get_parameters{#1:}[##1]%
+        \the#4%
+      \or
+        \def#8####1%
+          {\edef#3{####1}%
+           #6% checks parent and sets if needed
+           \mult_interfaces_get_parameters{#1#3:}[##2]%
+           \the#4}%
+        \processcommalist[##1]#8%
+      \or
+        \def#8####1%
+          {\edef#3{####1}%
+           \defcsname#1#3:\s!parent\endcsname{#1##2}%
+           \mult_interfaces_get_parameters{#1#3:}[##3]% always sets parent
+           \the#4}%
+        \processcommalist[##1]#8%
       \fi
-      \let#3#8}}
+      \let#3#7}}
 
-\protected\def\installautosetuphandler#1#2%
+\permanent\protected\def\installautosetuphandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_auto_setup_handler
         {\noexpand#1}% \??aa
         \expandafter\noexpand\csname setup#2\endcsname
         \expandafter\noexpand\csname current#2\endcsname
-        \expandafter\noexpand\csname setup_#2\endcsname % semi-public
         \expandafter\noexpand\csname everysetup#2\endcsname
         \expandafter\noexpand\csname setupcurrent#2\endcsname
         \expandafter\noexpand\csname check#2parent\endcsname
         \expandafter\noexpand\csname saved_setup_current#2\endcsname
         \expandafter\noexpand\csname nested_setup_current#2\endcsname}}
 
-\protected\def\installbasicparameterhandler#1#2%
+\permanent\protected\def\installbasicparameterhandler#1#2%
   {\installparameterhandler    {#1}{#2}%
    \installparameterhashhandler{#1}{#2}%
    \installparametersethandler {#1}{#2}%
    \installrootparameterhandler{#1}{#2}}
 
-\protected\def\installbasicautosetuphandler#1#2#3% \??self name \??parent (can be \??self)
+\permanent\protected\def\installbasicautosetuphandler#1#2#3% \??self name \??parent (can be \??self)
   {\installbasicparameterhandler{#1}{#2}%
    \installautosetuphandler     {#1}{#2}}
 
-\protected\def\installstylisticautosetuphandler#1#2#3% \??self name \??parent (can be \??self)
+\permanent\protected\def\installstylisticautosetuphandler#1#2#3% \??self name \??parent (can be \??self)
   {\installbasicparameterhandler{#1}{#2}%
    \installautosetuphandler     {#1}{#2}%
    \installstyleandcolorhandler {#1}{#2}}
 
-\protected\def\installcommandhandler#1#2#3% \??self name \??parent (can be \??self)
+\permanent\protected\def\installcommandhandler#1#2#3% \??self name \??parent (can be \??self)
   {\installbasicparameterhandler{#1}{#2}%
    \installdefinehandler        {#1}{#2}{#3}%
    \installsetuphandler         {#1}{#2}%
    \installstyleandcolorhandler {#1}{#2}}
 
-\protected\def\installswitchcommandhandler#1#2#3% \??self name \??parent (can be \??self)
+\permanent\protected\def\installswitchcommandhandler#1#2#3% \??self name \??parent (can be \??self)
   {\installbasicparameterhandler{#1}{#2}%
    \installdefinehandler        {#1}{#2}{#3}%
    \installswitchsetuphandler   {#1}{#2}%
    \installstyleandcolorhandler {#1}{#2}}
 
-\protected\def\installautocommandhandler#1#2#3% automatically defined cloned setups
+\permanent\protected\def\installautocommandhandler#1#2#3% automatically defined cloned setups
   {\installbasicparameterhandler{#1}{#2}%
    \installdefinehandler        {#1}{#2}{#3}%
    \installautosetuphandler     {#1}{#2}%
    \installstyleandcolorhandler {#1}{#2}}
 
-\protected\def\installsimplecommandhandler#1#2#3% no define (experiment) - use \check*parent when defining
+\permanent\protected\def\installsimplecommandhandler#1#2#3% no define (experiment) - use \check*parent when defining
   {\installbasicparameterhandler{#1}{#2}%
    \installsetuphandler         {#1}{#2}%
    \installstyleandcolorhandler {#1}{#2}}
@@ -741,13 +665,11 @@
 %D We don't need colons for such simple cases.
 
 \protected\def\mult_interfaces_install_direct_parameter_handler#1#2#3#4#5%
-%%{\def#3##1{\csname\ifcsname#1##1\endcsname#1##1\else\s!empty\fi\endcsname}%
-  {\def#3##1{\begincsname#1##1\endcsname}%
-   \def#4##1{\detokenize\expandafter\expandafter\expandafter{\csname#1##1\endcsname}}%
- % \def#4##1{\mult_interfaces_detokenize{\csname\ifcsname#1#2:##1\endcsname#1#2:##1\else\expandafter#5\csname#1#2:\s!parent\endcsname{##1}\fi\endcsname}}%
-   \def#5##1{\begincsname#1##1\endcsname}}
+  {\frozen\def#3##1{\begincsname#1##1\endcsname}%
+   \frozen\def#4##1{\detokenize\expandafter\expandafter\expandafter{\csname#1##1\endcsname}}%
+   \frozen\def#5##1{\begincsname#1##1\endcsname}}
 
-\protected\def\installdirectparameterhandler#1#2%
+\permanent\protected\def\installdirectparameterhandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_direct_parameter_handler
         {\noexpand#1}%
@@ -756,36 +678,28 @@
         \expandafter\noexpand\csname detokenized#2parameter\endcsname
         \expandafter\noexpand\csname direct#2parameter\endcsname}}
 
-\protected\def\mult_interfaces_install_direct_setup_handler#1#2#3#4#5%
-  {\protected\def#2{\dosingleempty#3}%
-   \newtoks#5%
-   \def#3[##1]{\mult_interfaces_get_parameters#1[##1]\the#5}%
-   \def#4{\mult_interfaces_get_parameters#1}}
+\protected\def\mult_interfaces_install_direct_setup_handler#1#2#3#4%
+  {\newtoks#4%
+   \frozen\protected\def#2[##1]{\ifarguments\or\mult_interfaces_get_parameters#1[##1]\fi\the#4}%
+   \frozen\def#3{\mult_interfaces_get_parameters#1}}
 
-\protected\def\installdirectsetuphandler#1#2%
+\permanent\protected\def\installdirectsetuphandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_direct_setup_handler
         {\noexpand#1}% \??aa
         \expandafter\noexpand\csname setup#2\endcsname
-        \expandafter\noexpand\csname setup_#2\endcsname % semi-public
         \expandafter\noexpand\csname setupcurrent#2\endcsname % no \every (we use 'current' for consistency)
         \expandafter\noexpand\csname everysetup#2\endcsname}}
 
-% \protected\def\mult_interfaces_install_direct_parameter_set_handler#1#2#3#4#5%
-%   {\protected\def#2{\mult_interfaces_def #1}%
-%    \protected\def#3{\mult_interfaces_edef#1}%
-%    \protected\def#4{\mult_interfaces_let #1}%
-%    \protected\def#5{\mult_interfaces_let #1\empty}}%
-
 % \startinterface english
     \protected\def\mult_interfaces_install_direct_parameter_set_handler#1#2#3#4#5%
-      {\protected\def#2##1{\expandafter \def\csname#1##1\endcsname}%
-       \protected\def#3##1{\expandafter\edef\csname#1##1\endcsname}%
-       \protected\def#4##1{\expandafter \let\csname#1##1\endcsname}%
-       \protected\def#5##1{\expandafter \let\csname#1##1\endcsname\empty}}%
+      {\frozen\protected\def#2##1{\defcsname#1##1\endcsname}%
+       \frozen\protected\def#3##1{\edefcsname#1##1\endcsname}%
+       \frozen\protected\def#4##1{\letcsname#1##1\endcsname}%
+       \frozen\protected\def#5##1{\letcsname#1##1\endcsname\empty}}%
 % \stopinterface
 
-\protected\def\installdirectparametersethandler#1#2%
+\permanent\protected\def\installdirectparametersethandler#1#2%
   {\normalexpanded
      {\mult_interfaces_install_direct_parameter_set_handler
         {\noexpand#1}% \??aa
@@ -794,15 +708,15 @@
         \expandafter\noexpand\csname let#2parameter\endcsname
         \expandafter\noexpand\csname reset#2parameter\endcsname}}
 
-\let\installdirectstyleandcolorhandler\installstyleandcolorhandler
+\aliased\let\installdirectstyleandcolorhandler\installstyleandcolorhandler
 
-\protected\def\installdirectcommandhandler#1#2%
+\permanent\protected\def\installdirectcommandhandler#1#2%
   {\installdirectparameterhandler    {#1}{#2}%
    \installdirectsetuphandler        {#1}{#2}%
    \installdirectparametersethandler {#1}{#2}%
    \installdirectstyleandcolorhandler{#1}{#2}}
 
-\protected\def\installsetuponlycommandhandler#1#2%
+\permanent\protected\def\installsetuponlycommandhandler#1#2%
   {\installdirectparameterhandler{#1}{#2}%
    \installdirectsetuphandler    {#1}{#2}%
   }% maybe \installdirectparametersethandler {#1}{#2}%
@@ -830,67 +744,48 @@
 % yes:\twoparameter{alpha}\par
 % yes:\twoparameter{beta}\par
 
-\protected\def\relateparameterhandlers#1#2#3#4% {from} {instance} {to} {instance}
-  {\expandafter\edef\csname\csname#1namespace\endcsname#2:\s!parent\endcsname{\csname#3namespace\endcsname#4}}
+\permanent\protected\def\relateparameterhandlers#1#2#3#4% {from} {instance} {to} {instance}
+  {\edefcsname\csname#1namespace\endcsname#2:\s!parent\endcsname{\csname#3namespace\endcsname#4}}
 
-\protected\def\relateparameterhandlersbyns#1#2#3#4% {from} {instance} {to} {instance}
-  {\expandafter\edef\csname#1#2:\s!parent\endcsname{#3#4}}
+\permanent\protected\def\relateparameterhandlersbyns#1#2#3#4% {from} {instance} {to} {instance}
+  {\edefcsname#1#2:\s!parent\endcsname{#3#4}}
 
 %D Here is another experiment:
 
-\protected\def\installactionhandler#1%
-  {\normalexpanded
-     {\mult_interfaces_install_action_handler
-        {#1}%
-        \expandafter\noexpand\csname current#1\endcsname
-        \expandafter\noexpand\csname setupcurrent#1\endcsname
-        \expandafter\noexpand\csname #1_action\endcsname}}
-
-% \protected\def\mult_interfaces_install_action_handler#1#2#3#4%
-%   {\protected\expandafter\def\csname#1\endcsname{\dodoubleempty#4}%
-%    \protected\def#4[##1][##2]%
-%      {\begingroup
-%       \ifsecondargument
-%         \edef#2{##1}%
-%         #3[##2]%
-%       \orelse\iffirstargument
-%         \doifelseassignment{##1}
-%           {\let#2\empty
-%            #3[##1]}%
-%           {\edef#2{##1}}%
-%       \else
-%         \let#2\empty
-%       \fi
-%       \directsetup{handler:action:#1}%
-%       \endgroup}}
-
-\protected\def\mult_interfaces_install_action_handler#1#2#3#4%
-  {\protected\expandafter\def\csname#1\endcsname{\dodoubleempty#4}%
-   \protected\def#4[##1][##2]%
+\protected\def\mult_interfaces_install_action_handler#1#2#3%
+%   {\frozen\tolerant\protected\expandafter\def\csname#1\endcsname[##1]##*[##2]%
+  {\frozen\tolerant\protected\defcsname#1\endcsname[##1]##*[##2]%
      {\begingroup
-      \ifsecondargument
-        \edef#2{##1}%
-        #3[##2]%
-      \orelse\iffirstargument
+      \ifarguments
+        \let#2\empty
+      \or
        %\ifcondition\expandafter\mult_check_for_assignment_indeed_begin_\detokenize{##1}=^^^^0003^^^^0003^^^^0004%
-%         \ifcondition\mult_aux_no_assignment_indeed##1\ignorearguments
-%           \edef#2{##1}%
-%         \else
-%           \let#2\empty
-%           #3[##1]%
-%         \fi
+      % \ifcondition\mult_aux_no_assignment_indeed##1\ignorearguments
+      %   \edef#2{##1}%
+      % \else
+      %   \let#2\empty
+      %   #3[##1]%
+      % \fi
         \ifhastok={##1}%
           \let#2\empty
           #3[##1]%
         \else
           \edef#2{##1}%
         \fi
-      \else
-        \let#2\empty
+      \or
+        \edef#2{##1}%
+        #3[##2]%
       \fi
       \directsetup{handler:action:#1}%
       \endgroup}}
 
+\permanent\protected\def\installactionhandler#1%
+  {\normalexpanded
+     {\mult_interfaces_install_action_handler
+        {#1}%
+        \expandafter\noexpand\csname current#1\endcsname
+        \expandafter\noexpand\csname setupcurrent#1\endcsname}}
+
 % First we had, in tune with the regular system variables:
 %
 % \starttyping
@@ -918,30 +813,23 @@
 
 \newcount\c_mult_interfaces_n_of_namespaces
 
-%def\v_interfaces_prefix_template{\number    \c_mult_interfaces_n_of_namespaces>}
-%def\v_interfaces_prefix_template{\characters\c_mult_interfaces_n_of_namespaces>}
-
-%def\v_interfaces_prefix_template % consistently %03i>
-% {\ifnum\c_mult_interfaces_n_of_namespaces<\plusten00\orelse\ifnum\c_mult_interfaces_n_of_namespaces<\plushundred0\fi
-%  \number\c_mult_interfaces_n_of_namespaces>}
-
 \def\v_interfaces_prefix_template
   {\number\c_mult_interfaces_n_of_namespaces>}
 
-\protected\def\installnamespace#1% for modules and users
+\permanent\protected\def\installnamespace#1% for modules and users
   {\ifcsname ????#1\endcsname
      \writestatus\m!system{duplicate user namespace '#1'}\wait
    \else
      \global\advance\c_mult_interfaces_n_of_namespaces\plusone
-     \expandafter\edef\csname ????#1\endcsname{\v_interfaces_prefix_template}%
+     \immutable\edefcsname ????#1\endcsname{\v_interfaces_prefix_template}%
    \fi}
 
-\protected\def\installcorenamespace#1%
+\permanent\protected\def\installcorenamespace#1%
   {\ifcsname ??#1\endcsname
      \writestatus\m!system{duplicate core namespace '#1'}\wait
    \else
      \global\advance\c_mult_interfaces_n_of_namespaces\plusone
-     \expandafter\edef\csname ??#1\endcsname{\v_interfaces_prefix_template}%
+     \immutable\edefcsname ??#1\endcsname{\v_interfaces_prefix_template}%
      \clf_registernamespace\c_mult_interfaces_n_of_namespaces{#1}%
    \fi}
 
@@ -961,20 +849,19 @@
 
 \letvalue\??dummy\empty
 
-          \def\dummyparameter           #1{\begincsname\??dummy#1\endcsname}
-          \def\directdummyparameter     #1{\begincsname\??dummy#1\endcsname}
-\protected\def\setdummyparameter        #1{\expandafter\def\csname\??dummy#1\endcsname}
-\protected\def\setexpandeddummyparameter#1{\expandafter\edef\csname\??dummy#1\endcsname}
-\protected\def\letdummyparameter        #1{\expandafter\let\csname\??dummy#1\endcsname}
+\permanent          \def\dummyparameter           #1{\begincsname\??dummy#1\endcsname}
+\permanent          \def\directdummyparameter     #1{\begincsname\??dummy#1\endcsname}
+\permanent\protected\def\setdummyparameter        #1{\defcsname\??dummy#1\endcsname}
+\permanent\protected\def\setexpandeddummyparameter#1{\edefcsname\??dummy#1\endcsname}
+\permanent\protected\def\letdummyparameter        #1{\letcsname\??dummy#1\endcsname}
 
-% \protected\def\getdummyparameters
-%   {\mult_interfaces_get_parameters\??dummy}
+\edef\mult_interfaces_dummy{\??dummy} % nor immutable
 
-\protected\def\getdummyparameters[#1%
+\permanent\protected\def\getdummyparameters[#1%
   {\if\noexpand#1]%
      \expandafter\gobbleoneargument
    \else
-     \let\m_mult_interfaces_namespace\??dummy
+     \let\m_mult_interfaces_namespace\mult_interfaces_dummy
      \expandafter\mult_interfaces_get_parameters_indeed
    \fi#1}
 
@@ -1025,13 +912,10 @@
 %
 % This is a user (module) command:
 
-\protected\def\definenamespace
-  {\dodoubleargument\mult_interfaces_define_name_space}
-
-\def\mult_interfaces_define_name_space[#1][#2]% namespace settings
+\permanent\tolerant\protected\def\definenamespace[#1]#*[#2]% namespace settings
   {\clf_definenamespace{#1}{#2}}
 
-\def\listnamespaces
+\permanent\protected\def\listnamespaces
   {\clf_listnamespaces}
 
 %D Helper:
@@ -1040,61 +924,52 @@
 %D \showparentchain{@@am}{left}
 %D \stoptyping
 
-\protected\def\showparentchain#1#2%
+\permanent\protected\def\showparentchain#1#2%
   {\writestatus\m!system{chain: [ \mult_interfaces_show_parent_chain{#1#2}]}}
 
-% \def\mult_interfaces_show_parent_chain#1%
-%   {#1 => %
-%    \ifcsname#1:\s!parent\endcsname
-%       \expandafter\mult_interfaces_show_parent_chain\csname#1:\s!parent\endcsname
-%    \fi}
-
 \def\mult_interfaces_show_parent_chain#1%
   {#1 => %
    \ifcsname#1:\s!parent\endcsname
-     %\expandafter\mult_interfaces_show_parent_chain\csname#1:\s!parent\endcsname
       \expandafter\mult_interfaces_show_parent_chain\lastnamedcs
    \fi}
 
 %D Another helper (needs to be applied):
 
-\protected\def\doifelsecommandhandler#1#2% namespace name
+\permanent\protected\def\doifelsecommandhandler#1#2% namespace name
   {\ifcsname#1#2:\s!parent\endcsname
      \expandafter\firstoftwoarguments
    \else
      \expandafter\secondoftwoarguments
    \fi}
 
-\let\doifcommandhandlerelse\doifelsecommandhandler
+\aliased\let\doifcommandhandlerelse\doifelsecommandhandler
 
-\protected\def\doifcommandhandler#1#2% namespace name
+\permanent\protected\def\doifcommandhandler#1#2% namespace name
   {\ifcsname#1#2:\s!parent\endcsname
      \expandafter\firstofoneargument
    \else
      \expandafter\gobbleoneargument
    \fi}
 
-\protected\def\doifnotcommandhandler#1#2% namespace name
+\permanent\protected\def\doifnotcommandhandler#1#2% namespace name
   {\ifcsname#1#2:\s!parent\endcsname
      \expandafter\gobbleoneargument
    \else
      \expandafter\firstofoneargument
    \fi}
 
-\let\doifcommandhandlerelse\doifelsecommandhandler
-
 % another set of (fast) helpers (grep for usage):
 
-\def\expandnamespaceparameter#1#2#3% \??xx \getp \c!xx \v!yy
+\permanent\def\expandnamespaceparameter#1#2#3% \??xx \getp \c!xx \v!yy
   {\csname#1\ifcsname#1\expandafter\expandafter\expandafter\mult_aux_expand_namespace_parameter#2#3}
 
 \def\mult_aux_expand_namespace_parameter#1#2% \cs \v!yy
   {#1\endcsname#1\else#2\fi\endcsname}
 
-\def\expandnamespacemacro#1#2#3% \??xx \some_edefed_cs \c!yy
+\permanent\def\expandnamespacemacro#1#2#3% \??xx \some_edefed_cs \c!yy
   {\csname#1\ifcsname#1#2\endcsname#2\else#3\fi\endcsname}
 
-\def\expandnamespacevalue#1#2% \??xx {...} \c!yy == optimized \expandcheckedcsname
+\permanent\def\expandnamespacevalue#1#2% \??xx {...} \c!yy == optimized \expandcheckedcsname
   {\csname#1\ifcsname#1\normalexpanded{\noexpand\syst_helpers_expand_checked_value{#2}}}
 
 \def\syst_helpers_expand_checked_value#1#2%
@@ -1120,11 +995,6 @@
 % many assignments and mechanism that do are also slow; the advantage is mostly nicer
 % in tracing
 
-\def\s!simple{simple}
-\def\s!single{single}
-\def\s!double{double}
-\def\s!triple{triple}
-
 \let\c_mult_set\relax
 
 \protected\def\mult_interfaces_install_definition_set#1#2#3#4#5#6#7%
@@ -1134,23 +1004,23 @@
      {\expandafter\let\expandafter\c_mult_set\csname #1_t_#6\endcsname
       \ifx\c_mult_set\relax
         \expandafter\newtoks\c_mult_set
-        \expandafter\let\csname #1_t_#6\endcsname\c_mult_set
+        \letcsname#1_t_#6\endcsname\c_mult_set
       \fi}
-   \protected\def#4##1%
+   \frozen\protected\def#4##1%
      {\pushmacro#6%
       \advance#3\plusone
       \edef#6{##1}%
       \unprotect}%
-   \protected\def#5%
+   \frozen\protected\def#5%
      {\protect
       \advance#3\minusone
       \popmacro#6}%
-   \protected\def#7##1%
+   \frozen\protected\def#7##1%
      {\edef#6{##1}%
       #2%
       \the\c_mult_set\relax}}
 
-\protected\def\installdefinitionset#1#2%
+\permanent\protected\def\installdefinitionset#1#2%
   {\normalexpanded
      {\mult_interfaces_install_definition_set
         {\noexpand#1}% \??aa
@@ -1163,20 +1033,16 @@
 
 \protected\def\mult_interfaces_install_definition_set_member#1#2#3#4#5#6#7#8#9% no everysetups etc
   {\let#5#2%
-   \protected\def#2%
+   \frozen\protected\def#2%
      {\ifcase#4\relax\expandafter#5\else\expandafter#6\fi}%
-   \protected\def#6%
-     {\dodoubleempty#7}%
-   \protected\def#7[##1][##2]%
-     {\ifsecondargument
-       %#3\c_mult_set\expandafter{\the\c_mult_set#9[##1][##2]}%
-        #3\toksapp\c_mult_set{#9[##1][##2]}%
-      \orelse\iffirstargument
-       %#3\c_mult_set\expandafter{\the\c_mult_set#8[##1]}%
-        #3\toksapp\c_mult_set{#8[##1]}%
+   \tolerant\protected\def#6[##1]##*[##2]%
+     {\ifarguments\or
+        #3\toksapp\c_mult_set{#7[##1]}%
+      \or
+        #3\toksapp\c_mult_set{#8[##1][##2]}%
       \fi}}
 
-\protected\def\installdefinitionsetmember#1#2#3#4%
+\permanent\protected\def\installdefinitionsetmember#1#2#3#4%
   {\normalexpanded
      {\mult_interfaces_install_definition_set_member
         {\noexpand#3}% \??aa
@@ -1185,58 +1051,33 @@
         \expandafter\noexpand\csname #2_nesting_depth\endcsname
         \expandafter\noexpand\csname normal_setup_#4\endcsname
         \expandafter\noexpand\csname delayed_setup_#4\endcsname
-        \expandafter\noexpand\csname do_delayed_setup_#4\endcsname
         \expandafter\noexpand\csname setup#4_\s!single\endcsname
         \expandafter\noexpand\csname setup#4_\s!double\endcsname}}
 
 %D Another experiment:
 
 \protected\def\mult_interfaces_install_parent_injector#1#2#3#4%
-  {\protected\def#4##1%
-    %{\ifx#3\empty
+  {\frozen\protected\def#4##1%
      {\ifempty#3%
-        \expandafter\def\csname#1#2:\s!parent\endcsname{#1##1}%
+        \defcsname#1#2:\s!parent\endcsname{#1##1}%
       \fi}}
 
-\protected\def\installparentinjector#1#2%
+\permanent\protected\def\installparentinjector#1#2%
   {\normalexpanded{\mult_interfaces_install_parent_injector
      {\noexpand#1}%
      \expandafter\noexpand\csname current#2\endcsname
      \expandafter\noexpand\csname current#2parent\endcsname
      \expandafter\noexpand\csname inject#2parent\endcsname}}
 
-% 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.
-
-% \protected\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}
-%
-% \protected\def\installmacrostack      #1{\syst_helpers_install_macro_stack#1\let \??localpushedmacro }
-% \protected\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.
 
-\protected\def\installmacrostack#1%
+\permanent\protected\def\installmacrostack#1%
   {\ifdefined#1\else\let#1\empty\fi
    \protected\expandafter\gdef\csname push_macro_\csstring#1\endcsname{\localpushmacro#1}%
    \protected\expandafter\gdef\csname  pop_macro_\csstring#1\endcsname{\localpopmacro #1}}
 
-
-\protected\def\installglobalmacrostack#1%
+\permanent\protected\def\installglobalmacrostack#1%
   {\ifdefined#1\else\glet#1\empty\fi
    \protected\expandafter\gdef\csname push_macro_\csstring#1\endcsname{\globalpushmacro#1}%
    \protected\expandafter\gdef\csname  pop_macro_\csstring#1\endcsname{\globalpopmacro #1}}
@@ -1307,30 +1148,26 @@
 \installcorenamespace{commalistprocessornext}
 \installcorenamespace{commalistprocessoraction}
 
-\protected\def\installcommalistprocessor#1#2% 5 macro names overhead
-  {\protected\expandafter\edef\csname\??commalistprocessor#1\endcsname[%
-  %  {\noexpand\futureexpandis]%
-  %     \noexpand\gobbleoneargument
-  %     \csname\??commalistprocessorpickup#1\endcsname}
-  %\protected\expandafter\edef\csname\??commalistprocessorpickup#1\endcsname
+\permanent\protected\def\installcommalistprocessor#1#2% 5 macro names overhead
+  {\protected\edefcsname\??commalistprocessor#1\endcsname[%
      {\csname\??commalistprocessorwrap#1\endcsname\relax}% \relax preserves {}
-   \protected\expandafter\edef\csname\??commalistprocessorwrap#1\endcsname##1]%
+   \protected\edefcsname\??commalistprocessorwrap#1\endcsname##1]%
      {\csname\??commalistprocessorfirst#1\endcsname##1,]}
-   \protected\expandafter\edef\csname\??commalistprocessorfirst#1\endcsname\relax
+   \protected\edefcsname\??commalistprocessorfirst#1\endcsname\relax
      {\csname\??commalistprocessornext#1\endcsname}%
-   \protected\expandafter\edef\csname\??commalistprocessornext#1\endcsname
+   \protected\edefcsname\??commalistprocessornext#1\endcsname
      {\noexpand\futureexpandis]%
         \noexpand\gobbleoneargument
         \csname\??commalistprocessoraction#1\endcsname}
-   \protected\expandafter\edef\csname\??commalistprocessoraction#1\endcsname##1,%
+   \protected\edefcsname\??commalistprocessoraction#1\endcsname##1,%
      {\noexpand#2{##1}%
       \csname\??commalistprocessornext#1\endcsname}}
 
-\protected\def\installcommalistprocessorcommand#1#2% \processor \action
+\permanent\protected\def\installcommalistprocessorcommand#1#2% \processor \action
   {\edef\p_name{\csstring#2}%
    \installcommalistprocessor\p_name{#2}%
    \expandafter\let\expandafter#1\csname\??commalistprocessor\p_name\endcsname}
 
-\protected\def\commalistprocessor#1{\csname\??commalistprocessor#1\endcsname}
+\permanent\protected\def\commalistprocessor#1{\csname\??commalistprocessor#1\endcsname}
 
 \protect \endinput