stable 2013.05.28 00:36

1 files changed, 85 insertions, 290 deletions

diff --git a/tex/context/base/math-stc.mkvi b/tex/context/base/math-stc.mkvi
index 76a07db5c..2dc2b2c22 100644
--- a/tex/context/base/math-stc.mkvi
+++ b/tex/context/base/math-stc.mkvi
@@ -48,10 +48,6 @@
 %D
 %D In the end we have a more flexible mechanism which also handles text variants.
 
-%D When wrapping up some math developments I decided to add mp support here
-%D as well. A nice evening job with Joe Bonamassa performing live on the big
-%D screen (real nice bluray's). See meta-imp-mat.mkiv for examples.
-
 % possible improvements:
 %
 % - we could skip the left/right offsets when offset=normal, this saves some access time
@@ -60,40 +56,27 @@
 
 \installcorenamespace {mathextensiblefallbacks}
 
-% currently no italic correction ... problem is that we don't know yet if we have an italic
-% below so we we need to postpone
-
 \def\math_stackers_fallback
   {\hbox to \scratchwidth{\csname\??mathextensiblefallbacks\ifcsname\??mathextensiblefallbacks\number\scratchunicode\endcsname\number\scratchunicode\fi\endcsname}}
  %{\csname\??mathextensiblefallbacks\ifcsname\??mathextensiblefallbacks\number\scratchunicode\endcsname\number\scratchunicode\fi\endcsname }
 
-% \def\math_stackers_regular
-%   {\mathstylehbox{\Umathaccent\fam\zerocount\scratchunicode{\hskip\scratchwidth}}}
-
 \def\math_stackers_regular
-  {\mathstylehbox{\usemathstackerscolorparameter\c!color
-                  \Umathaccent\fam\zerocount\scratchunicode{\hskip\scratchwidth}}}
+  {\mathstylehbox{\Umathaccent\fam\zerocount\scratchunicode{\hskip\scratchwidth}}}
 
 \def\math_stackers_stretch % we don't have that one yet
-  {\mathstylehbox{\usemathstackerscolorparameter\c!color
-                  \Umathaccent\fam\zerocount\scratchunicode{\hskip\hsize}}}
-
-% these delimiters are a unuseable as theu don't center for small arguments:
-%
-% $\Umathaccent   0 0 "2190{x}$ \par $\Umathaccent   0 0 "27F8{x}$\par
-% $\Udelimiterunder 0 "2190{x}$ \par $\Udelimiterunder 0 "27F8{x}$\par
+  {\mathstylehbox{\Umathaccent\fam\zerocount\scratchunicode{\hskip\hsize}}}
 
 \setvalue{\??mathextensiblefallbacks}{\hbox{\vrule\!!width\scratchwidth\!!height.1\exheight\!!depth\zeropoint}}
 
-% \def\math_stackers_with_fallback#codepoint%
-%   {\begingroup
-%    \scratchunicode#codepoint\relax
-%    \ifcase\mathextensiblecode\fam\scratchunicode\relax
-%      \math_stackers_fallback
-%    \else
-%      \math_stackers_stretch
-%    \fi
-%    \endgroup}
+\def\math_stackers_with_fallback#codepoint%
+  {\begingroup
+   \scratchunicode#codepoint\relax
+   \ifcase\mathextensiblecode\fam\scratchunicode\relax
+     \math_stackers_fallback
+   \else
+     \math_stackers_stretch
+   \fi
+   \endgroup}
 
 %D We don't really need this because we can assume that fonts have the right
 %D extensibles. If needed I will make a general virtual extender for \OPENTYPE\
@@ -131,12 +114,6 @@
   [%c!alternative=\v!text,    % text | mathematics
    \c!left=,
    \c!right=,
-   \c!mathclass=\s!rel,
-   \c!alternative=\v!normal,
-   \c!mp=math:stacker:\number\scratchunicode,
-   \c!mpheight=\exheight,
-   \c!mpdepth=\exheight,
-   \c!mpoffset=.25\exheight,
    \c!voffset=.25\exheight,
    \c!hoffset=.5\emwidth,
    \c!minheight=\exheight,
@@ -144,7 +121,7 @@
    \c!minwidth=\emwidth,
    \c!order=\v!normal,
    \c!strut=,
-   \c!color=, % todo: when I need it
+  %\c!color=, % todo: when I need it
    \c!topcommand=,
    \c!middlecommand=,
    \c!bottomcommand=,
@@ -155,7 +132,6 @@
 %D top of the baseline by default.
 
 \installcorenamespace {mathstackerslocation}
-\installcorenamespace {mathstackersalternative}
 
 \letvalue{\??mathstackerslocation\v!top    }\plusone   % on top of baseline
 \letvalue{\??mathstackerslocation\v!high   }\plustwo   % 25 % down
@@ -196,23 +172,6 @@
      \math_stackers_fallback
    \fi}
 
-% no checking, we assume sane use
-
-\letvalue{\??mathstackersalternative\v!normal }\math_stackers_content
-\letvalue{\??mathstackersalternative\v!default}\math_stackers_content
-
-\setvalue{\??mathstackersalternative\v!mp}%
-  {\hbox\bgroup %  todo: add code key + tag
-   \edef\overlaywidth    {\the\scratchwidth}%
-   \edef\overlayheight   {\the\dimexpr\mathstackersparameter\c!mpheight}%
-   \edef\overlaydepth    {\the\dimexpr\mathstackersparameter\c!mpdepth}%
-   \edef\overlayoffset   {\the\dimexpr\mathstackersparameter\c!mpoffset}%
-   \edef\overlaylinewidth{\the\linewidth}%
-   \edef\overlaylinecolor{\mathstackersparameter\c!color}%
-   \edef\p_mp{\mathstackersparameter\c!mp}%
-   \uniqueMPgraphic{\p_mp}%
-   \egroup}
-
 \def\math_stackers_check_unicode#codepoint%
   {\scratchunicode#codepoint\relax
    \scratchhoffset\mathstackersparameter\c!hoffset\relax
@@ -264,12 +223,11 @@
   {\begingroup
    \edef\currentmathstackers{#category}%
    \mathstackersparameter\c!left\relax
-   \ifmmode\math_class_by_parameter\mathstackersparameter\else\dontleavehmode\fi
-     {\edef\p_offset     {\mathstackersparameter\c!offset}%
-      \edef\p_location   {\mathstackersparameter\c!location}%
-      \edef\p_order      {\mathstackersparameter\c!order}%
-      \edef\p_strut      {\mathstackersparameter\c!strut}%
-      \edef\p_alternative{\mathstackersparameter\c!alternative}%
+   \ifmmode\mathrel\else\dontleavehmode\fi
+     {\edef\p_offset  {\mathstackersparameter\c!offset}%
+      \edef\p_location{\mathstackersparameter\c!location}%
+      \edef\p_order   {\mathstackersparameter\c!order}%
+      \edef\p_strut   {\mathstackersparameter\c!strut}%
       \ifx\p_order\v!reverse
         \edef\m_math_stackers_text_top   {#bottomtext}%
         \edef\m_math_stackers_text_bottom{#toptext}%
@@ -327,17 +285,17 @@
       \advance\scratchwidth2\scratchhoffset
       %
       \ifcase#method\relax
-        \setbox\scratchboxthree\csname\??mathstackersalternative\p_alternative\endcsname
+        \setbox\scratchboxthree\math_stackers_content
       \fi
       %
       \ifdim\wd\scratchboxone<\scratchwidth
-        \setbox\scratchboxone\hbox to \scratchwidth{\hss\unhbox\scratchboxone\hss}% unhboxing makes leaders work
+        \setbox\scratchboxone\hbox to \scratchwidth{\hss\box\scratchboxone\hss}%
       \fi
       \ifdim\wd\scratchboxtwo<\scratchwidth
-        \setbox\scratchboxtwo\hbox to \scratchwidth{\hss\unhbox\scratchboxtwo\hss}%
+        \setbox\scratchboxtwo\hbox to \scratchwidth{\hss\box\scratchboxtwo\hss}%
       \fi
       \ifdim\wd\scratchboxthree<\scratchwidth
-        \setbox\scratchboxthree\hbox to \scratchwidth{\hss\unhbox\scratchboxthree\hss}%
+        \setbox\scratchboxthree\hbox to \scratchwidth{\hss\box\scratchboxthree\hss}%
       \fi
       %
       \ifcsname\??mathstackerslocation\p_location\endcsname
@@ -437,30 +395,17 @@
 
 %D The next one deals with under and over extensibles (arrows mostly):
 
-\installcorenamespace {mathclasses}
-
-\letvalue{\??mathclasses    }\mathord
-\letvalue{\??mathclasses rel}\mathrel
-\letvalue{\??mathclasses ord}\mathord
-
-\def\math_class_by_parameter#1%
-  {\normalexpanded{\noexpand\math_class_by_parameter_indeed{#1\c!mathclass}}}
-
-\def\math_class_by_parameter_indeed#1%
-  {\csname\??mathclasses\ifcsname\??mathclasses#1\endcsname#1\fi\endcsname}
-
-\unexpanded\def\math_stackers_make_double#top#bottom#category#codepoint#codeextra#text%
+\unexpanded\def\math_stackers_double#where#category#codepoint#text%
   {\begingroup
    \edef\currentmathstackers{#category}%
    \mathstackersparameter\c!left\relax
-   \ifmmode\math_class_by_parameter\mathstackersparameter\else\dontleavehmode\fi
+   \ifmmode\mathrel\else\dontleavehmode\fi
      {\edef\currentmathstackers{#category}%
       \edef\m_math_stackers_text_middle {#text}%
       %
-      \edef\p_offset     {\mathstackersparameter\c!offset}%
-      \edef\p_location   {\mathstackersparameter\c!location}%
-      \edef\p_strut      {\mathstackersparameter\c!strut}%
-      \edef\p_alternative{\mathstackersparameter\c!alternative}%
+      \edef\p_offset  {\mathstackersparameter\c!offset}%
+      \edef\p_location{\mathstackersparameter\c!location}%
+      \edef\p_strut   {\mathstackersparameter\c!strut}%
       %
       \scratchleftoffset \zeropoint
       \scratchrightoffset\zeropoint
@@ -480,7 +425,7 @@
       \fi
       \advance\scratchwidth2\scratchhoffset
       %
-      \setbox\scratchboxtwo  \csname\??mathstackersalternative\p_alternative\endcsname
+      \setbox\scratchboxtwo  \math_stackers_content
       \setbox\scratchboxthree\hbox to \scratchwidth{\hss\box\scratchboxthree\hss}%
       %
       \math_stackers_normalize_three
@@ -491,74 +436,49 @@
       %
       \ifdim\htdp\scratchboxtwo>\zeropoint
         \kern-\scratchwidth
-        \ifcase#top\else
+        \ifcase#where\relax
           \math_stackers_top\bgroup
-          % \raise\dimexpr\scratchheight+\scratchtopoffset\relax
-            \raise\dimexpr\scratchheight+\mathstackersparameter\c!voffset\relax
+            \raise\dimexpr\scratchheight+\scratchtopoffset\relax
             \box\scratchboxtwo
           \egroup
-        \fi
-        \scratchunicode#codeextra\relax
-        \ifcase\scratchunicode\else
-          \kern-\scratchwidth
-          \setbox\scratchboxtwo\csname\??mathstackersalternative\p_alternative\endcsname
-        \fi
-        \ifcase#bottom\else
+        \else
           \math_stackers_bottom\bgroup
-          % \lower\dimexpr\scratchdepth+\ht\scratchboxtwo+\scratchbottomoffset\relax
-            \lower\dimexpr\scratchdepth+\ht\scratchboxtwo+\mathstackersparameter\c!voffset\relax
+            \lower\dimexpr\scratchdepth+\ht\scratchboxtwo+\scratchbottomoffset\relax
             \box\scratchboxtwo
           \egroup
         \fi
       \fi}%
   \mathstackersparameter\c!right\relax
-  \edef\p_limits{\mathstackersparameter\c!mathlimits}%
-  \ifx\p_limits\v!yes
-    \expandafter\endgroup\expandafter\limits
-  \else
-    \expandafter\endgroup
-  \fi}
-
-\unexpanded\def\definemathoverextensible  {\dotripleempty   \math_extensibles_define_over }
-\unexpanded\def\definemathunderextensible {\dotripleempty   \math_extensibles_define_under}
-\unexpanded\def\definemathdoubleextensible{\doquadrupleempty\math_extensibles_define_double}
-
-\def\math_extensibles_define_over[#1][#2][#3]%
-  {\ifthirdargument
-     \setuevalue{#2}{\math_stackers_make_double\plusone  \zerocount{#1}{\number#3}{0}}%
-   \else
-     \setuevalue{#1}{\math_stackers_make_double\plusone  \zerocount\noexpand\currentmathstackers{\number#2}{0}}%
-   \fi}
+  \endgroup}
 
-\def\math_extensibles_define_under[#1][#2][#3]%
+\unexpanded\def\definemathoverextensible {\dotripleempty\math_extensiblies_define_over }
+\unexpanded\def\definemathunderextensible{\dotripleempty\math_extensiblies_define_under}
+
+\def\math_extensiblies_define_over[#1][#2][#3]%
   {\ifthirdargument
-     \setuevalue{#2}{\math_stackers_make_double\zerocount\plusone{#1}{\number#3}{0}}%
+     \setuevalue{#2}{\math_stackers_double\zerocount{#1}{\number#3}}%
    \else
-     \setuevalue{#1}{\math_stackers_make_double\zerocount\plusone\noexpand\currentmathstackers{\number#2}{0}}%
+     \setuevalue{#1}{\math_stackers_double\zerocount\noexpand\currentmathstackers{\number#2}}%
    \fi}
 
-\def\math_extensibles_define_double[#1][#2][#3][#4]%
-  {\iffourthargument
-     \setuevalue{#2}{\math_stackers_make_double\plusone  \plusone{#1}{\number#3}{\number#4}}%
+\def\math_extensiblies_define_under[#1][#2][#3]%
+  {\ifthirdargument
+     \setuevalue{#2}{\math_stackers_double\plusone{#1}{\number#3}}%
    \else
-     \setuevalue{#1}{\math_stackers_make_double\plusone  \plusone\noexpand\currentmathstackers{\number#2}{\number#3}}%
+     \setuevalue{#1}{\math_stackers_double\plusone\noexpand\currentmathstackers{\number#2}}%
    \fi}
 
-\unexpanded\def\mathover  {\begingroup\dosingleempty\math_stackers_handle_over  }
-\unexpanded\def\mathunder {\begingroup\dosingleempty\math_stackers_handle_under }
-\unexpanded\def\mathdouble{\begingroup\dodoubleempty\math_stackers_handle_double}
+\unexpanded\def\mathover {\begingroup\dosingleempty\math_stackers_handle_over }
+\unexpanded\def\mathunder{\begingroup\dosingleempty\math_stackers_handle_under}
 
 \def\math_stackers_handle_over[#category]%
-  {\math_stackers_direct_double\plusone\zerocount{\iffirstargument#category\else\v!top   \fi}} % will be defined later on
+  {\math_stackers_handle_double\zerocount{\iffirstargument#category\else\v!top   \fi}} % will be defined later on
 
 \def\math_stackers_handle_under[#category]#codepoint#bottomtext%
-  {\math_stackers_direct_double\zerocount\plusone{\iffirstargument#category\else\v!bottom\fi}} % will be defined later on
-
-\def\math_stackers_handle_double[#category]#codepoint#bottomtext%
-  {\math_stackers_direct_double\plusone\plusone  {\iffirstargument#category\else\v!bottom\fi}} % will be defined later on
+  {\math_stackers_handle_double\plusone  {\iffirstargument#category\else\v!bottom\fi}} % will be defined later on
 
-\def\math_stackers_direct_double#top#bottom#category#codepoint#text%
-  {\math_stackers_make_double#top#bottom{#category}{#codepoint}{#text}%
+\def\math_stackers_handle_double#location#category#codepoint#text%
+  {\math_stackers_double#location{#category}{#codepoint}{#text}%
    \endgroup}
 
 %D Here is a bonus macro that takes three texts. It can be used to get consistent
@@ -638,79 +558,23 @@
   [\c!order=\v!reverse]
 
 \definemathstackers
-  [\v!both]
+  [\v!top]
   [\v!mathematics]
-  [\c!location=\v!top, % ?
+  [\c!location=\v!top,
    \c!strut=\v!no,
    \c!middlecommand=\mathematics,
    \c!hoffset=\zeropoint]
 
 \definemathstackers
-  [\v!top]
-  [\v!both]
-
-\definemathstackers
   [\v!bottom]
-  [\v!both]
-
-\definemathstackers
-  [vfenced]
-  [\v!both]
-  [\c!mathclass=\s!ord,
-   \c!mathlimits=\v!yes]
+  [\v!mathematics]
+  [\c!location=\v!top,
+   \c!strut=\v!no,
+   \c!middlecommand=\mathematics,
+   \c!hoffset=\zeropoint]
 
 % These are compatibity definitions, math only.
 
-% todo: top= bottom= middle= is nicer (compare math-fen)
-
-%D We save a few definitions that we automatically got from the \type {char-def.lua}
-%D database.
-
-% Be careful in choosing what accents you take (the code below uses a
-% combining one):
-%
-% \startbuffer
-% % $\Umathaccent top        0 0 "20D7 {example}$
-% % $\Umathaccent top  fixed 0 0 "20D7 {example}$
-% $\Umathaccent              0 0 "20D7 {example}$
-% $\Umathaccent        fixed 0 0 "20D7 {example}$
-% $\Umathaccent bottom       0 0 "20D7 {example}$
-% $\Umathaccent bottom fixed 0 0 "20D7 {example}$
-% $\Umathaccent both         0 0 "20D7
-%                            0 0 "20D7 {example}$
-% $\Umathaccent both fixed   0 0 "20D7
-%                    fixed   0 0 "20D7 {example}$
-% $\Umathaccent both         0 0 "20D7
-%                    fixed   0 0 "20D7 {example}$
-% $\Umathaccent both fixed   0 0 "20D7
-%                            0 0 "20D7 {example}$
-% \stopbuffer
-%
-% \setupbodyfont[modern]  \getbuffer
-% \setupbodyfont[xits]    \getbuffer
-% \setupbodyfont[cambria] \getbuffer
-
-\unexpanded\def\normaldoublebrace {\Umathaccents 0 \defaultmathfamily "23DE 0 \defaultmathfamily "23DF }
-\unexpanded\def\normaldoubleparent{\Umathaccents 0 \defaultmathfamily "23DC 0 \defaultmathfamily "23DD }
-
-% let's keep this
-
-\let\normaloverbrace      \overbrace
-\let\normalunderbrace     \underbrace
-\let\normaloverparent     \overparent
-\let\normalunderparent    \underparent
-\let\normaloverbracket    \overbracket
-\let\normalunderbracket   \underbracket
-\let\normalunderleftarrow \underleftarrow
-\let\normaloverleftarrow  \overleftarrow
-\let\normalunderrightarrow\underrightarrow
-\let\normaloverrightarrow \overrightarrow
-
-\let\lceil                \lceiling
-\let\rceil                \rceiling
-
-%D Here come the new ones:
-
 \definemathstackers [\v!none]   [\v!mathematics] [\c!hoffset=\zeropoint]
 \definemathstackers [\v!normal] [\v!mathematics] [\c!hoffset=0.5\emwidth] % the default
 \definemathstackers [\v!small]  [\v!mathematics] [\c!hoffset=1\emwidth]
@@ -719,12 +583,8 @@
 
 \definemathextensible [\v!reverse] [xrel]                ["002D]
 \definemathextensible [\v!reverse] [xequal]              ["003D]
-\definemathextensible [\v!reverse] [xleftarrow]          ["2190] % ["27F5]
-\definemathextensible [\v!reverse] [xrightarrow]         ["2192] % ["27F6]
-\definemathextensible [\v!reverse] [xleftrightarrow]     ["27F7]
-\definemathextensible [\v!reverse] [xLeftarrow]          ["27F8]
-\definemathextensible [\v!reverse] [xRightarrow]         ["27F9]
-\definemathextensible [\v!reverse] [xLeftrightarrow]     ["27FA]
+\definemathextensible [\v!reverse] [xleftarrow]          ["2190]
+\definemathextensible [\v!reverse] [xrightarrow]         ["2192]
 \definemathextensible [\v!reverse] [xtwoheadleftarrow]   ["219E]
 \definemathextensible [\v!reverse] [xtwoheadrightarrow]  ["21A0]
 \definemathextensible [\v!reverse] [xmapsto]             ["21A6]
@@ -738,15 +598,15 @@
 \definemathextensible [\v!reverse] [xleftrightharpoons]  ["21CB]
 \definemathextensible [\v!reverse] [xrightleftharpoons]  ["21CC]
 \definemathextensible [\v!reverse] [xtriplerel]          ["2261]
+\definemathextensible [\v!reverse] [xleftrightarrow]     ["27F7]
+\definemathextensible [\v!reverse] [xLeftarrow]          ["27F8]
+\definemathextensible [\v!reverse] [xRightarrow]         ["27F9]
+\definemathextensible [\v!reverse] [xLeftrightarrow]     ["27FA]
 
 \definemathextensible [\v!mathematics] [mrel]                ["002D]
 \definemathextensible [\v!mathematics] [mequal]              ["003D]
-\definemathextensible [\v!mathematics] [mleftarrow]          ["2190] % ["27F5]
-\definemathextensible [\v!mathematics] [mrightarrow]         ["2192] % ["27F6]
-\definemathextensible [\v!mathematics] [mleftrightarrow]     ["27F7]
-\definemathextensible [\v!mathematics] [mLeftarrow]          ["27F8]
-\definemathextensible [\v!mathematics] [mRightarrow]         ["27F9]
-\definemathextensible [\v!mathematics] [mLeftrightarrow]     ["27FA]
+\definemathextensible [\v!mathematics] [mleftarrow]          ["2190]
+\definemathextensible [\v!mathematics] [mrightarrow]         ["2192]
 \definemathextensible [\v!mathematics] [mtwoheadleftarrow]   ["219E]
 \definemathextensible [\v!mathematics] [mtwoheadrightarrow]  ["21A0]
 \definemathextensible [\v!mathematics] [mmapsto]             ["21A6]
@@ -760,18 +620,18 @@
 \definemathextensible [\v!mathematics] [mleftrightharpoons]  ["21CB]
 \definemathextensible [\v!mathematics] [mrightleftharpoons]  ["21CC]
 \definemathextensible [\v!mathematics] [mtriplerel]          ["2261]
+\definemathextensible [\v!mathematics] [mleftrightarrow]     ["27F7]
+\definemathextensible [\v!mathematics] [mLeftarrow]          ["27F8]
+\definemathextensible [\v!mathematics] [mRightarrow]         ["27F9]
+\definemathextensible [\v!mathematics] [mLeftrightarrow]     ["27FA]
 
 \definemathextensible [\v!text] [trel]                ["002D]
 \definemathextensible [\v!text] [tequal]              ["003D]
-\definemathextensible [\v!text] [tmapsto]             ["21A6]
-\definemathextensible [\v!text] [tleftarrow]          ["2190] % ["27F5]
-\definemathextensible [\v!text] [trightarrow]         ["2192] % ["27F6]
-\definemathextensible [\v!text] [tleftrightarrow]     ["27F7]
-\definemathextensible [\v!text] [tLeftarrow]          ["27F8]
-\definemathextensible [\v!text] [tRightarrow]         ["27F9]
-\definemathextensible [\v!text] [tLeftrightarrow]     ["27FA]
+\definemathextensible [\v!text] [tleftarrow]          ["2190]
+\definemathextensible [\v!text] [trightarrow]         ["2192]
 \definemathextensible [\v!text] [ttwoheadleftarrow]   ["219E]
 \definemathextensible [\v!text] [ttwoheadrightarrow]  ["21A0]
+\definemathextensible [\v!text] [tmapsto]             ["21A6]
 \definemathextensible [\v!text] [thookleftarrow]      ["21A9]
 \definemathextensible [\v!text] [thookrightarrow]     ["21AA]
 \definemathextensible [\v!text] [tleftharpoondown]    ["21BD]
@@ -782,59 +642,30 @@
 \definemathextensible [\v!text] [tleftrightharpoons]  ["21CB]
 \definemathextensible [\v!text] [trightleftharpoons]  ["21CC]
 \definemathextensible [\v!text] [ttriplerel]          ["2261]
+\definemathextensible [\v!text] [tleftrightarrow]     ["27F7]
+\definemathextensible [\v!text] [tLeftarrow]          ["27F8]
+\definemathextensible [\v!text] [tRightarrow]         ["27F9]
+\definemathextensible [\v!text] [tLeftrightarrow]     ["27FA]
 
-\definemathoverextensible [\v!top] [overleftarrow]         ["2190] % ["27F5]
-\definemathoverextensible [\v!top] [overrightarrow]        ["2192] % ["27F6]
-\definemathoverextensible [\v!top] [overleftrightarrow]    ["27F7]
-\definemathoverextensible [\v!top] [overtwoheadleftarrow]  ["27F8]
-\definemathoverextensible [\v!top] [overtwoheadrightarrow] ["27F9]
+\definemathoverextensible [\v!top] [overleftarrow]         ["2190]
+\definemathoverextensible [\v!top] [overrightarrow]        ["2192]
 \definemathoverextensible [\v!top] [overleftharpoondown]   ["21BD]
 \definemathoverextensible [\v!top] [overleftharpoonup]     ["21BC]
 \definemathoverextensible [\v!top] [overrightharpoondown]  ["21C1]
 \definemathoverextensible [\v!top] [overrightharpoonup]    ["21C0]
+\definemathoverextensible [\v!top] [overleftrightarrow]    ["27F7]
+\definemathoverextensible [\v!top] [overtwoheadleftarrow]  ["27F8]
+\definemathoverextensible [\v!top] [overtwoheadrightarrow] ["27F9]
 
-\definemathunderextensible [\v!bottom] [underleftarrow]         ["2190] % ["27F5]
-\definemathunderextensible [\v!bottom] [underrightarrow]        ["2192] % ["27F6]
-\definemathunderextensible [\v!bottom] [underleftrightarrow]    ["27F7]
-\definemathunderextensible [\v!bottom] [undertwoheadleftarrow]  ["27F8]
-\definemathunderextensible [\v!bottom] [undertwoheadrightarrow] ["27F9]
+\definemathunderextensible [\v!bottom] [underleftarrow]         ["2190]
+\definemathunderextensible [\v!bottom] [underrightarrow]        ["2192]
 \definemathunderextensible [\v!bottom] [underleftharpoondown]   ["21BD]
 \definemathunderextensible [\v!bottom] [underleftharpoonup]     ["21BC]
 \definemathunderextensible [\v!bottom] [underrightharpoondown]  ["21C1]
 \definemathunderextensible [\v!bottom] [underrightharpoonup]    ["21C0]
-
-% We don't use overline and underline. This is one of the overlooked aspects of
-% unicode cq. opentype math: why treat rules different than e.g. arrows and
-% accents. It is a bit unfortunate that the opportunity to move math to new
-% technologies happened outside the tex domain (and/or some aspects were kept
-% while in fact they were side effects of limitations of traditional fonts).
-% From the unicode aware tex engines' implementation point of view things
-% could have been done a bit nicer but then: the community didn't seem to care
-% too much and just has to follow now.
-%
-% Anyhow, we use a character based approach so that at least we get unicode
-% stuff in the backend (okay, we still need to deal with some cut and paste
-% issues but at least we now know what we deal with.
-
-% alternatively we can move the original to FE*
-
-\definemathoverextensible   [vfenced] [overbar]       ["FE33E]          % ["203E]
-\definemathunderextensible  [vfenced] [underbar]      ["FE33F]          % ["203E]
-\definemathdoubleextensible [vfenced] [doublebar]     ["FE33E] ["FE33F]
-
-\definemathoverextensible   [vfenced] [overbrace]     ["FE3DE]          % ["023DE]
-\definemathunderextensible  [vfenced] [underbrace]    ["FE3DF]          % ["023DF]
-\definemathdoubleextensible [vfenced] [doublebrace]   ["FE3DE] ["FE3DF]
-
-\definemathoverextensible   [vfenced] [overparent]    ["FE3DC]          % ["023DC]
-\definemathunderextensible  [vfenced] [underparent]   ["FE3DD]          % ["023DD]
-\definemathdoubleextensible [vfenced] [doubleparent]  ["FE3DC] ["FE3DD]
-
-\definemathoverextensible   [vfenced] [overbracket]   ["FE3B4]          % ["023B4]
-\definemathunderextensible  [vfenced] [underbracket]  ["FE3B5]          % ["023B5]
-\definemathdoubleextensible [vfenced] [doublebracket] ["FE3B4] ["FE3B5]
-
-% \unexpanded\def\mathopwithlimits#1#2{\mathop{#1{#2}}\limits}
+\definemathunderextensible [\v!bottom] [underleftrightarrow]    ["27F7]
+\definemathunderextensible [\v!bottom] [undertwoheadleftarrow]  ["27F8]
+\definemathunderextensible [\v!bottom] [undertwoheadrightarrow] ["27F9]
 
 %D Some bonus ones (for the moment here):
 
@@ -865,7 +696,7 @@
       #3%
       \endgroup}}
 
-% These will be defined in char-def as well once we have \leaders<number>
+% These will be defined in char-def as well:
 
 \unexpanded\def\rightarrowfill        {\math_stackers_hacked_fill \relbar                   \relbar                      \rightarrow}
 \unexpanded\def\leftarrowfill         {\math_stackers_hacked_fill \leftarrow                \relbar                      \relbar    }
@@ -903,7 +734,6 @@
   {\expandafter\let\csname\??mathextensiblefallbacks\number#2\expandafter\endcsname\csname#1\endcsname
    \expandafter\let\csname                                 #1\expandafter\endcsname\csname#1\endcsname}
 
-\defineextensiblefiller [barfill]                ["203E]
 \defineextensiblefiller [relfill]                ["002D]
 \defineextensiblefiller [equalfill]              ["003D]
 \defineextensiblefiller [leftarrowfill]          ["2190]
@@ -925,7 +755,6 @@
 \defineextensiblefiller [Leftarrowfill]          ["27F8]
 \defineextensiblefiller [Rightarrowfill]         ["27F9]
 \defineextensiblefiller [Leftrightarrowfill]     ["27FA]
-\defineextensiblefiller [Leftrightarrowfill]     ["27FA]
 
 %D Extra:
 
@@ -937,40 +766,6 @@
 % \mathchardef\doublebond"003D
 % \mathchardef\triplebond"2261
 
-%D Also handy:
-
-\unexpanded\def\definemathunstacked
-  {\dotripleempty\math_stackers_define_unstacked_normal}
-
-\def\math_stackers_define_unstacked_normal[#1][#2][#3]% category name unicode
-  {\ifthirdargument
-     \setuevalue{#2}{\math_stackers_unstacked_normal{#1}{\number#3}}%
-   \else
-     \setuevalue{#1}{\math_stackers_unstacked_normal\noexpand\currentmathstackers{\number#2}}%
-   \fi}
-
-\unexpanded\def\math_stackers_unstacked_normal#category#codepoint%
-  {\begingroup
-   \edef\currentmathstackers{#category}%
-   \edef\p_moffset{\mathstackersparameter\c!moffset}%
-   \ifx\p_moffset\empty \else
-     \mskip\scratchmuskip
-   \fi
-   \ifmmode\math_class_by_parameter\mathstackersparameter\else\dontleavehmode\fi
-     {\usemathstackerscolorparameter\c!color
-      \Umathchar\zerocount\defaultmathfamily#codepoint}%
-   \ifx\p_moffset\empty \else
-     \mskip\scratchmuskip
-   \fi
-   \endgroup}
-
-\definemathstackers  [\v!wide] [\c!moffset=\thickmuskip,\c!mathclass=\s!rel]
-
-\definemathunstacked [\v!wide] [And]       ["0026] % \mathrel{\;&\;}
-\definemathunstacked [\v!wide] [impliedby] ["27F8] % \mathrel{\;\Longleftarrow\;}
-\definemathunstacked [\v!wide] [implies]   ["27F9] % \mathrel{\;\Longrightarrow\;}
-\definemathunstacked [\v!wide] [iff]       ["27FA] % \mathrel{\;\Longleftrightarrow\;}
-
 \protect \endinput
 
 % \mathrel{\mathop{\hbox to \dimen0{\hss\copy4\hss}}