beta 2013.08.20 12:31

32 files changed, 228 insertions, 268 deletions

diff --git a/tex/context/base/char-def.lua b/tex/context/base/char-def.lua
index 86e6eef2a..7902ad95a 100644
--- a/tex/context/base/char-def.lua
+++ b/tex/context/base/char-def.lua
@@ -990,7 +990,7 @@ characters.data={
   direction="on",
   linebreak="op",
   mathclass="open",
-  mathname="lbrack",
+  mathname="lbracket",
   mirror=0x005D,
   unicodeslot=0x005B,
  },
@@ -1014,7 +1014,7 @@ characters.data={
   direction="on",
   linebreak="cp",
   mathclass="close",
-  mathname="rbrack",
+  mathname="rbracket",
   mirror=0x005B,
   unicodeslot=0x005D,
  },
@@ -61520,6 +61520,8 @@ characters.data={
   description="NABLA",
   direction="on",
   linebreak="ai",
+  mathclass="default",
+  mathname="nabla",
   unicodeslot=0x2207,
  },
  [0x2208]={
@@ -61746,8 +61748,20 @@ characters.data={
   description="SQUARE ROOT",
   direction="on",
   linebreak="ai",
-  mathclass="radical",
-  mathname="surd",
+  mathspec={
+   {
+    class="root",
+    name="rootradical",
+   },
+   {
+    class="radical",
+    name="surdradical",
+   },
+   {
+    class="ordinary",
+    name="surd",
+   },
+  },
   unicodeslot=0x221A,
  },
  [0x221B]={
@@ -173811,7 +173825,6 @@ characters.data={
  },
  [0x1D6FB]={
   category="sm",
-  comment="mathname='nabla'",
   description="MATHEMATICAL ITALIC NABLA",
   direction="l",
   linebreak="al",
diff --git a/tex/context/base/cont-new.mkiv b/tex/context/base/cont-new.mkiv
index 462293d37..13bfcc907 100644
--- a/tex/context/base/cont-new.mkiv
+++ b/tex/context/base/cont-new.mkiv
@@ -11,7 +11,7 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-\newcontextversion{2013.08.17 00:58}
+\newcontextversion{2013.08.20 12:31}
 
 %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/context-version.pdf b/tex/context/base/context-version.pdf
index 2f1e7f2fb..9b5a5f67e 100644
--- a/tex/context/base/context-version.pdf
+++ b/tex/context/base/context-version.pdf
diff --git a/tex/context/base/context.mkiv b/tex/context/base/context.mkiv
index 184a9f356..c4747fd46 100644
--- a/tex/context/base/context.mkiv
+++ b/tex/context/base/context.mkiv
@@ -25,7 +25,7 @@
 %D up and the dependencies are more consistent.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2013.08.17 00:58}
+\edef\contextversion{2013.08.20 12:31}
 \edef\contextkind   {beta}
 
 %D For those who want to use this:
@@ -420,7 +420,7 @@
 \loadmarkfile{math-ini}
 \loadmarkfile{math-pln}
 \loadmarkfile{math-for}
-\loadmarkfile{math-def}
+\loadmarkfile{math-def} % also saves some meanings
 \loadmarkfile{math-ali}
 %loadmarkfile{math-arr}
 \loadmkvifile{math-stc}
diff --git a/tex/context/base/font-con.lua b/tex/context/base/font-con.lua
index 091058075..2e35d3ad7 100644
--- a/tex/context/base/font-con.lua
+++ b/tex/context/base/font-con.lua
@@ -475,7 +475,7 @@ function constructors.scale(tfmdata,specification)
     --
     target.postprocessors = tfmdata.postprocessors
     --
-    local targetslant         = (parameters.slant         or parameters[1] or 0)
+    local targetslant         = (parameters.slant         or parameters[1] or 0) -- *hdelta ? needs checking
     local targetspace         = (parameters.space         or parameters[2] or 0)*hdelta
     local targetspace_stretch = (parameters.space_stretch or parameters[3] or 0)*hdelta
     local targetspace_shrink  = (parameters.space_shrink  or parameters[4] or 0)*hdelta
diff --git a/tex/context/base/math-def.mkiv b/tex/context/base/math-def.mkiv
index 4b881d705..cc75252aa 100644
--- a/tex/context/base/math-def.mkiv
+++ b/tex/context/base/math-def.mkiv
@@ -15,7 +15,7 @@
 
 \unprotect
 
-% this will be done at the lua end
+%D Some day this will be done at the lua end.
 
 \startluacode
     mathematics.define(\number\defaultmathfamily)
@@ -24,22 +24,8 @@
 
 \activatemathcharacters
 
-% will go to math-ext (if used at all)
-
-\Umathchardef\braceld=0 \defaultmathfamily "FF07A
-\Umathchardef\bracerd=0 \defaultmathfamily "FF07B
-\Umathchardef\bracelu=0 \defaultmathfamily "FF07C
-\Umathchardef\braceru=0 \defaultmathfamily "FF07D
-
-% ctx specific
-
-% \bgroup
-% \catcode`|=\othercatcode
-% \global\let\|=|
-% \egroup
-
-% The \mfunction macro is an alternative for \hbox with a
-% controlable font switch.
+%D The \mfunction macro is an alternative for \hbox with a controlable font
+%D switch.
 
 \definemathcommand [arccos]  [nolop] {\mfunctionlabeltext{arccos}}
 \definemathcommand [arcsin]  [nolop] {\mfunctionlabeltext{arcsin}}
@@ -69,7 +55,7 @@
 \definemathcommand [max]     [limop] {\mfunctionlabeltext{max}}
 \definemathcommand [min]     [limop] {\mfunctionlabeltext{min}}
 \definemathcommand [mod]     [limop] {\mfunctionlabeltext{mod}}
-%definemathcommand [div]     [limop] {\mfunctionlabeltext{div}}                              % overloads \div symbol
+%definemathcommand [div]     [limop] {\mfunctionlabeltext{div}}      % overloads \div symbol
 \definemathcommand [projlim] [limop] {\mfunctionlabeltext{projlim}}
 \definemathcommand [Pr]      [limop] {\mfunctionlabeltext{Pr}}
 \definemathcommand [sec]     [nolop] {\mfunctionlabeltext{sec}}
@@ -79,170 +65,23 @@
 \definemathcommand [tanh]    [nolop] {\mfunctionlabeltext{tanh}}
 \definemathcommand [tan]     [nolop] {\mfunctionlabeltext{tan}}
 
-% \definemathcommand [integers]      {{\mathblackboard Z}}
-% \definemathcommand [reals]         {{\mathblackboard R}}
-% \definemathcommand [rationals]     {{\mathblackboard Q}}
-% \definemathcommand [naturalnumbers]{{\mathblackboard N}}
-% \definemathcommand [complexes]     {{\mathblackboard C}}
-% \definemathcommand [primes]        {{\mathblackboard P}}
-
 \let\normalmatharg\arg % todo: maybe automatically
 
-% moved to fences
-%
-% methods:
-%
-% 1: none
-% 2: lua
-% 3: tex
-%
-% variants:
-%
-% 1: step 1
-% 2: step 2
-% 3: htdp * 1.33^n
-% 4: size * 1.33^n
-%
-% \setnewconstant\bigmathdelimitermethod \plusone
-% \setnewconstant\bigmathdelimitervariant\plusthree
-%
-% \unexpanded\def\plainbigdelimiters % traditional method
-%   {\bigmathdelimitermethod\plustwo}
-%
-% \plainbigdelimiters % is default for the moment but not so nice
-%
-% \def\doleftbigmath #1{\ifx#1\relax\else\left#1\fi}
-% \def\dorightbigmath#1{\ifx#1\relax\else\right.\fi}
-%
-% \installcorenamespace{mathbig}
-%
-% \unexpanded\def\choosemathbig#1#2% so we accept \big{||} as well
-%   {{\hbox{$%
-%       \ifcase\bigmathdelimitermethod
-%         \doleftbigmath#2\relax
-%         \dorightbigmath#2\relax
-%       \or
-%         \attribute\mathsizeattribute\numexpr\bigmathdelimitervariant*\plushundred+#1\relax
-%         \doleftbigmath#2\relax
-%         \dorightbigmath#2\relax
-%       \else
-%         \doleftbigmath#2\relax
-%         \vbox to\getvalue{\??mathbig\number#1}\bodyfontsize{}%
-%         \dorightbigmath#2\relax
-%       \fi
-%       \nulldelimiterspace\zeropoint\relax
-%       \mathsurround\zeropoint
-%   $}}}
-%
-% \unexpanded\def\mathdelimiterstep#1#2%
-%   {\begingroup
-%    \attribute\mathsizeattribute\numexpr\plushundred+#1\relax
-%    \doleftbigmath#2\relax
-%    \dorightbigmath#2\relax
-%    \endgroup}
-%
-% \definemathcommand [big]  {\choosemathbig\plusone  }
-% \definemathcommand [Big]  {\choosemathbig\plustwo  }
-% \definemathcommand [bigg] {\choosemathbig\plusthree}
-% \definemathcommand [Bigg] {\choosemathbig\plusfour }
-%
-% \definemathcommand [bigl]  [open]  [one] {\big}
-% \definemathcommand [bigm]  [rel]   [one] {\big}
-% \definemathcommand [bigr]  [close] [one] {\big}
-% \definemathcommand [Bigl]  [open]  [one] {\Big}
-% \definemathcommand [Bigm]  [rel]   [one] {\Big}
-% \definemathcommand [Bigr]  [close] [one] {\Big}
-% \definemathcommand [biggl] [open]  [one] {\bigg}
-% \definemathcommand [biggm] [rel]   [one] {\bigg}
-% \definemathcommand [biggr] [close] [one] {\bigg}
-% \definemathcommand [Biggl] [open]  [one] {\Bigg}
-% \definemathcommand [Biggm] [rel]   [one] {\Bigg}
-% \definemathcommand [Biggr] [close] [one] {\Bigg}
-
 %D This needs checking:
 
-\def\setoperatorlimits#1#2% operator limits
+\unexpanded\def\setoperatorlimits#1#2% operator limits
   {\savenormalmeaning{#1}%
-   \def#1{\csname normal\strippedcsname#1\endcsname#2}}
-
-\setoperatorlimits\int              \intlimits
-\setoperatorlimits\iint             \intlimits
-\setoperatorlimits\iiint            \intlimits
-\setoperatorlimits\oint             \intlimits
-\setoperatorlimits\oiint            \intlimits
-\setoperatorlimits\oiiint           \intlimits
-\setoperatorlimits\intclockwise     \intlimits
-\setoperatorlimits\ointclockwise    \intlimits
-\setoperatorlimits\ointctrclockwise \intlimits
-
-%D This is a temporary hack until we figure out how to do this correctly,
-%D preferably using math parameters but we can also consider doing some
-%D node juggling here.
-
-\unexpanded\def\implies  {\mathrel{\;\Longrightarrow\;}}
-\unexpanded\def\impliedby{\mathrel{\;\Longleftarrow\;}}
-\unexpanded\def\And      {\mathrel{\;\internalAnd\;}}
-%unexpanded\def\iff      {\;\Longleftrightarrow\;}
-\setuvalue          {iff}{\;\Longleftrightarrow\;} % nicer for if checker
-
-% todo: virtual in math-vfu
-
-% \definemathcommand [mapsto]         {\mapstochar\rightarrow}
-% \definemathcommand [hookrightarrow] {\lhook\joinrel\rightarrow}
-% \definemathcommand [hookleftarrow]  {\leftarrow\joinrel\rhook}
-% \definemathcommand [bowtie]         {\mathrel\triangleright\joinrel\mathrel\triangleleft}
-% \definemathcommand [models]         {\mathrel|\joinrel=}
-% \definemathcommand [iff]            {\;\Longleftrightarrow\;}
-
-% hm
-
-% ldots = 2026
-% vdots = 22EE
-% cdots = 22EF
-% ddots = 22F1
-% udots = 22F0
-
-% \def\PLAINldots{\ldotp\ldotp\ldotp}
-% \def\PLAINcdots{\cdotp\cdotp\cdotp}
-
-% \def\PLAINvdots
-%   {\vbox{\baselineskip.4\bodyfontsize\lineskiplimit\zeropoint\kern.6\bodyfontsize\hbox{.}\hbox{.}\hbox{.}}}
-
-% \def\PLAINddots
-%   {\mkern1mu%
-%    \raise.7\bodyfontsize\vbox{\kern.7\bodyfontsize\hbox{.}}%
-%    \mkern2mu%
-%    \raise.4\bodyfontsize\relax\hbox{.}%
-%    \mkern2mu%
-%    \raise.1\bodyfontsize\hbox{.}%
-%    \mkern1mu}
-
-% \definemathcommand [ldots] [inner]   {\PLAINldots}
-% \definemathcommand [cdots] [inner]   {\PLAINcdots}
-% \definemathcommand [vdots] [nothing] {\PLAINvdots}
-% \definemathcommand [ddots] [inner]   {\PLAINddots}
-
-%D \starttyping
-%D $\sqrt[3]{10}$
-%D \stoptyping
-%D
-%D This root command will be overloaded later:
-
-\def\rootradical{\Uroot \defaultmathfamily "221A } % can be done in char-def
-
-\def\root#1\of{\rootradical{#1}} % #2
-
-\unexpanded\def\sqrt{\doifnextoptionalelse\rootwithdegree\rootwithoutdegree}
-
-\def\rootwithdegree   [#1]{\rootradical{#1}}
-\def\rootwithoutdegree    {\rootradical  {}}
-
-\definemathcommand [mathstrut] {\vphantom{(}}
-\definemathcommand [joinrel]   {\mathrel{\mkern-3mu}}
-
-\unexpanded\def\{{\mathortext\lbrace\letterleftbrace } % or maybe a chardef
-\unexpanded\def\}{\mathortext\rbrace\letterrightbrace} % or maybe a chardef
-\unexpanded\def\|{\mathortext\vert  \letterbar       } % or maybe a chardef
+   \expandafter\def\expandafter#1\expandafter{\csname normal\strippedcsname#1\endcsname#2}}
+
+\setoperatorlimits \int              \intlimits
+\setoperatorlimits \iint             \intlimits
+\setoperatorlimits \iiint            \intlimits
+\setoperatorlimits \oint             \intlimits
+\setoperatorlimits \oiint            \intlimits
+\setoperatorlimits \oiiint           \intlimits
+\setoperatorlimits \intclockwise     \intlimits
+\setoperatorlimits \ointclockwise    \intlimits
+\setoperatorlimits \ointctrclockwise \intlimits
 
 %D The following colon related definitions are provided by Aditya
 %D Mahajan who derived them from \type {mathtools.sty} and \type
@@ -288,7 +127,7 @@
 \definemathcommand  [doublecolonsep]  {\mkern-0.9mu}
 
 %D Now we define all the colon relations .. needs checking with char-def.lua ...
-%d will move to a separate module.
+%D will move to a separate module.
 
 \definemathcommand [centercolon]      [rel] {\mathstylevcenteredhbox\colon}
 \definemathcommand [colonminus]       [rel] {\centercolon\colonsep\mathrel{-}}
@@ -348,9 +187,6 @@
 
 % let's keep this
 
-\def\Umathbotaccent{\Umathaccent \s!bottom }
-\def\Umathaccents  {\Umathaccent \s!both   }
-
 \let\normaloverbrace      \overbrace
 \let\normalunderbrace     \underbrace
 \let\normaloverparent     \overparent
@@ -365,34 +201,9 @@
 \unexpanded\def\mathopwithlimits#1#2{\mathop{#1{#2}}\limits}
 \unexpanded\def\stackrel        #1#2{\mathrel{\mathop{#2}\limits^{#1}}}
 
-% these are stackers now
-
-%\unexpanded\def\overbrace      {\mathopwithlimits\normaloverbrace      }
-%\unexpanded\def\underbrace     {\mathopwithlimits\normalunderbrace     }
-%\unexpanded\def\doublebrace    {\mathopwithlimits\normaldoublebrace    }
-%\unexpanded\def\overparent     {\mathopwithlimits\normaloverparent     }
-%\unexpanded\def\underparent    {\mathopwithlimits\normalunderparent    }
-%\unexpanded\def\overbracket    {\mathopwithlimits\normaloverbracket    }
-%\unexpanded\def\underbracket   {\mathopwithlimits\normalunderbracket   }
-%\unexpanded\def\doubleparent   {\mathopwithlimits\normaldoubleparent   }
-
-%unexpanded\def\underleftarrow {\mathopwithlimits\normalunderleftarrow }
-%unexpanded\def\overleftarrow  {\mathopwithlimits\normaloverleftarrow  }
-%unexpanded\def\underrightarrow{\mathopwithlimits\normalunderrightarrow}
-%unexpanded\def\overrightarrow {\mathopwithlimits\normaloverrightarrow }
-
 \let\lceil \lceiling
 \let\rceil \rceiling
 
-\let\normalsurd\surd
-
-\unexpanded\def\surd{\normalsurd{}}
-
-% Some special characters:
-
-\unexpanded\def\nabla{∇} % this one adapts
-
-%
 % todo mathclass=punctuation ord
 
 % \Umathcode"02C="6 \defaultmathfamily "02C
diff --git a/tex/context/base/math-fen.mkiv b/tex/context/base/math-fen.mkiv
index 9ad1a1ec1..2a05ac5a1 100644
--- a/tex/context/base/math-fen.mkiv
+++ b/tex/context/base/math-fen.mkiv
@@ -56,17 +56,17 @@
 
 \def\math_fenced_left  {\edef\p_left{\mathfenceparameter\c!left}%
                         \math_fenced_color_push
-                        \normalleft\ifx\p_left\empty.\else\Udelimiter\plusfour\fam\p_left\fi
+                        \normalleft\ifx\p_left\empty.\else\Udelimiter\plusfour\fam\p_left\relax\fi
                         \math_fenced_color_pop}
 \def\math_fenced_middle{\edef\p_middle{\mathfenceparameter\c!middle}%
                         \mskip\thinmuskip
                         \math_fenced_color_push
-                        \normalmiddle\ifx\p_middle\empty.\else\Udelimiter\plusfour\fam\p_middle\fi
+                        \normalmiddle\ifx\p_middle\empty.\else\Udelimiter\plusfour\fam\p_middle\relax\fi
                         \math_fenced_color_pop
                         \mskip\thinmuskip}
 \def\math_fenced_right {\edef\p_right{\mathfenceparameter\c!right}%
                         \math_fenced_color_push
-                        \normalright\ifx\p_right\empty.\else\Udelimiter\plusfive\fam\p_right\fi
+                        \normalright\ifx\p_right\empty.\else\Udelimiter\plusfive\fam\p_right\relax\fi
                         \math_fenced_color_pop}
 
 \def\math_fenced_color_do_push{\pushcolor[\p_math_fenced_color]}
@@ -178,25 +178,48 @@
 \setvalue{\??mathright \s!unknown}{\setfalse\c_math_fenced_done\ifconditional\c_math_fenced_unknown\normalright \nexttoken\fi}
 \setvalue{\??mathmiddle\s!unknown}{\setfalse\c_math_fenced_done\ifconditional\c_math_fenced_unknown\normalmiddle\nexttoken\fi}
 
-\bgroup
-
-    \let\temp [ \global\expandafter\let\csname\??mathleft\meaning\temp\endcsname\Lbracket
-    \let\temp ( \global\expandafter\let\csname\??mathleft\meaning\temp\endcsname\Lparent
-    \let\temp < \global\expandafter\let\csname\??mathleft\meaning\temp\endcsname\Langle
-    \let\temp { \global\expandafter\let\csname\??mathleft\meaning\temp\endcsname\Lbrace
-    \let\temp | \global\expandafter\let\csname\??mathleft\meaning\temp\endcsname\Lbar
-    \let\temp ‖ \global\expandafter\let\csname\??mathleft\meaning\temp\endcsname\Ldoublebar
-    \let\temp . \global\expandafter\let\csname\??mathleft\meaning\temp\endcsname\Lnothing
-
-    \let\temp ] \global\expandafter\let\csname\??mathright\meaning\temp\endcsname\Rbracket
-    \let\temp ) \global\expandafter\let\csname\??mathright\meaning\temp\endcsname\Rparent
-    \let\temp > \global\expandafter\let\csname\??mathright\meaning\temp\endcsname\Rangle
-    \let\temp } \global\expandafter\let\csname\??mathright\meaning\temp\endcsname\Rbrace
-    \let\temp | \global\expandafter\let\csname\??mathright\meaning\temp\endcsname\Rbar
-    \let\temp ‖ \global\expandafter\let\csname\??mathright\meaning\temp\endcsname\Rdoublebar
-    \let\temp . \global\expandafter\let\csname\??mathright\meaning\temp\endcsname\Rnothing
-
-\egroup
+\unexpanded\def\installmathfencepair#1#2#3#4%
+  {\expandafter\let\csname\??mathleft \meaning#1\endcsname#2%
+   \expandafter\let\csname\??mathright\meaning#3\endcsname#4}
+
+\expandafter\let\csname\??mathleft\meaning  [\endcsname\Lbracket
+\expandafter\let\csname\??mathleft\meaning  (\endcsname\Lparent
+\expandafter\let\csname\??mathleft\meaning  <\endcsname\Langle
+\expandafter\let\csname\??mathleft\meaning  {\endcsname\Lbrace
+\expandafter\let\csname\??mathleft\meaning  |\endcsname\Lbar
+\expandafter\let\csname\??mathleft\meaning  ‖\endcsname\Ldoublebar
+\expandafter\let\csname\??mathleft\meaning  .\endcsname\Lnothing
+
+\expandafter\let\csname\??mathright\meaning ]\endcsname\Rbracket
+\expandafter\let\csname\??mathright\meaning )\endcsname\Rparent
+\expandafter\let\csname\??mathright\meaning >\endcsname\Rangle
+\expandafter\let\csname\??mathright\meaning }\endcsname\Rbrace
+\expandafter\let\csname\??mathright\meaning |\endcsname\Rbar
+\expandafter\let\csname\??mathright\meaning ‖\endcsname\Rdoublebar
+\expandafter\let\csname\??mathright\meaning .\endcsname\Rnothing
+
+\let\lbrack\lbracket
+\let\rbrack\rbracket
+
+\installmathfencepair \lbrace   \Lbrace   \rbrace   \Rbrace
+\installmathfencepair \lbracket \Lbracket \rbracket \Rbracket
+\installmathfencepair \lparent  \Lparent  \rparent  \Rparent
+\installmathfencepair \langle   \Langle   \rangle   \Rangle
+%installmathfencepair \lbar     \Lbar     \rbar     \Rbar
+
+\unexpanded\def\{{\mathortext\lbrace  \letterleftbrace   } % or maybe a chardef
+\unexpanded\def\}{\mathortext\rbrace  \letterrightbrace  } % or maybe a chardef
+\unexpanded\def\[{\mathortext\lbracket\letterleftbracket } % or maybe a chardef
+\unexpanded\def\]{\mathortext\rbracket\letterrightbracket} % or maybe a chardef
+\unexpanded\def\({\mathortext\lparent \letterleftparent  } % or maybe a chardef
+\unexpanded\def\){\mathortext\rparent \letterrightparent } % or maybe a chardef
+\unexpanded\def\|{\mathortext\vert    \letterbar         } % or maybe a chardef
+
+\installmathfencepair \{ \Lbrace   \} \Rbrace
+\installmathfencepair \[ \Lbracket \] \Rbracket
+\installmathfencepair \( \Lparent  \) \Rparent
+\installmathfencepair \< \Langle   \> \Rangle
+\installmathfencepair \| \Lbar     \| \Rbar
 
 %D As we have overloaded \type {\left} and \type {\right} we also need a more
 %D clever version of the following:
@@ -296,4 +319,12 @@
 % \definemathoverextensible [top] [hoed]  ["FE302]
 % \definemathoverextensible [top] [slang] ["FE303]
 
+%D The next characters were used for constructing nicer extensibles but
+%D nowadays we have real characters.
+
+\Umathchardef\braceld=0 \defaultmathfamily "FF07A
+\Umathchardef\bracerd=0 \defaultmathfamily "FF07B
+\Umathchardef\bracelu=0 \defaultmathfamily "FF07C
+\Umathchardef\braceru=0 \defaultmathfamily "FF07D
+
 \protect
diff --git a/tex/context/base/math-ini.lua b/tex/context/base/math-ini.lua
index c6d96dab2..6be06e634 100644
--- a/tex/context/base/math-ini.lua
+++ b/tex/context/base/math-ini.lua
@@ -90,6 +90,7 @@ local classes = allocate {
     large       =  1, -- op
     variable    =  7, -- alphabetic
     number      =  7, -- alphabetic
+    root        = 16, -- a private one
 }
 
 local open_class   = 4
@@ -154,6 +155,10 @@ local function radical(family,slot)
     return formatters['\\Uradical "%X "%X '](family,slot)
 end
 
+local function root(family,slot)
+    return formatters['\\Uroot "%X "%X '](family,slot)
+end
+
 local function mathchardef(name,class,family,slot)
     return formatters['\\Umathchardef\\%s "%X "%X "%X '](name,class,family,slot)
 end
@@ -194,29 +199,42 @@ local setmathcharacter = function(class,family,slot,unicode,mset,dset)
     return mset, dset
 end
 
+local f_accent    = formatters[ [[\ugdef\%s{\Umathaccent 0 "%X "%X }]] ]
+local f_topaccent = formatters[ [[\ugdef\%s{\Umathaccent 0 "%X "%X }]] ]
+local f_botaccent = formatters[ [[\ugdef\%s{\Umathbotaccent 0 "%X "%X }]] ]
+local f_over      = formatters[ [[\ugdef\%s{\Udelimiterover "%X "%X }]] ]
+local f_under     = formatters[ [[\ugdef\%s{\Udelimiterunder "%X "%X }]] ]
+local f_fence     = formatters[ [[\ugdef\%s{\Udelimiter "%X "%X "%X }]] ]
+local f_delimiter = formatters[ [[\ugdef\%s{\Udelimiter 0 "%X "%X }]] ]
+local f_radical   = formatters[ [[\ugdef\%s{\Uradical "%X "%X }]] ]
+local f_root      = formatters[ [[\ugdef\%s{\Uroot "%X "%X }]] ]
+----- f_char      = formatters[ [[\ugdef\%s{\Umathchar "%X "%X "%X }]]
+local f_char      = formatters[ [[\Umathchardef\%s "%X "%X "%X ]] ]
+
 local setmathsymbol = function(name,class,family,slot) -- hex is nicer for tracing
     if class == classes.accent then
-        contextsprint(formatters[ [[\ugdef\%s{\Umathaccent 0 "%X "%X }]] ](name,family,slot))
+        contextsprint(f_accent(name,family,slot))
     elseif class == classes.topaccent then
-        contextsprint(formatters[ [[\ugdef\%s{\Umathaccent 0 "%X "%X }]] ](name,family,slot))
+        contextsprint(f_topaccent(name,family,slot))
     elseif class == classes.botaccent then
-        contextsprint(formatters[ [[\ugdef\%s{\Umathbotaccent 0 "%X "%X }]] ](name,family,slot))
+        contextsprint(f_botaccent(name,family,slot))
     elseif class == classes.over then
-        contextsprint(formatters[ [[\ugdef\%s{\Udelimiterover "%X "%X }]] ](name,family,slot))
+        contextsprint(f_over(name,family,slot))
     elseif class == classes.under then
-        contextsprint(formatters[ [[\ugdef\%s{\Udelimiterunder "%X "%X }]] ](name,family,slot))
+        contextsprint(f_under(name,family,slot))
     elseif class == open_class or class == close_class or class == middle_class then
         setdelcode("global",slot,{family,slot,0,0})
-        contextsprint(formatters[ [[\ugdef\%s{\Udelimiter "%X "%X "%X }]] ](name,class,family,slot))
+        contextsprint(f_fence(name,class,family,slot))
     elseif class == classes.delimiter then
         setdelcode("global",slot,{family,slot,0,0})
-        contextsprint(formatters[ [[\ugdef\%s{\Udelimiter 0 "%X "%X }]] ](name,family,slot))
+        contextsprint(f_delimiter(name,family,slot))
     elseif class == classes.radical then
-        contextsprint(formatters[ [[\ugdef\%s{\Uradical "%X "%X }]] ](name,family,slot))
+        contextsprint(f_radical(name,family,slot))
+    elseif class == classes.root then
+        contextsprint(f_root(name,family,slot))
     else
         -- beware, open/close and other specials should not end up here
-     -- contextsprint(formatters[ [[\ugdef\%s{\Umathchar "%X "%X "%X }]],name,class,family,slot))
-        contextsprint(formatters[ [[\Umathchardef\%s "%X "%X "%X ]] ](name,class,family,slot))
+        contextsprint(f_char(name,class,family,slot))
     end
 end
 
diff --git a/tex/context/base/math-ini.mkiv b/tex/context/base/math-ini.mkiv
index f386cdd30..bac46cbec 100644
--- a/tex/context/base/math-ini.mkiv
+++ b/tex/context/base/math-ini.mkiv
@@ -45,6 +45,13 @@
 \registerctxluafile{math-tag}{1.001}
 \registerctxluafile{math-fbk}{1.001}
 
+%D A few compatibility helpers:
+
+\def\Umathbotaccent{\Umathaccent \s!bottom }
+\def\Umathaccents  {\Umathaccent \s!both   }
+
+%D The attributes that we will use:
+
 \definesystemattribute[mathalphabet]   [public]
 \definesystemattribute[mathsize]       [public]
 \definesystemattribute[mathpunctuation][public]
@@ -355,6 +362,11 @@
 \unexpanded\def\mathcommand#1%
   {\csname\??mathcommand#1\endcsname}
 
+%D Let's define a few comands here:
+
+\definemathcommand [mathstrut] {\vphantom{(}}
+\definemathcommand [joinrel]   {\mathrel{\mkern-3mu}}
+
 %D Moved from font-ini.mkiv:
 %D
 %D \macros
@@ -500,10 +512,6 @@
 %D \tt test $\sin{(x^{\sin(x^{\sin(x)})})}$ test
 %D \stoptyping
 
-%D Some goodies:
-
-\unexpanded\def\Angstrom{\nomathematics{\Aring}}
-
 %D \macros
 %D   {nonknuthmode, donknuthmode}
 %D
@@ -679,8 +687,8 @@
 
 \newconditional \knuthmode
 
-\let\nonknuthmode\relax
-\let\donknuthmode\relax
+\let\nonknuthmode\relax % no longer needed in MkIV
+\let\donknuthmode\relax % no longer needed in MkIV
 
 % \def\nonknuthmode
 %   {\pushcatcodetable
diff --git a/tex/context/base/math-rad.mkvi b/tex/context/base/math-rad.mkvi
index b9d4021c3..b3a6a24c9 100644
--- a/tex/context/base/math-rad.mkvi
+++ b/tex/context/base/math-rad.mkvi
@@ -15,18 +15,33 @@
 
 \unprotect
 
-%D This is already defined in math-def.mkiv:
+%D \starttyping
+%D $\sqrt[3]{10}$
+%D \stoptyping
+%D
+%D This root command will be overloaded later:
 
-% \def\rootradical{\Uroot \defaultmathfamily "221A } % can be done in char-def
-%
-% \def\root#1\of{\rootradical{#1}} % #2
-%
-% A traditional approach:
-%
-% \unexpanded\def\sqrt{\doifnextoptionalelse\rootwithdegree\rootwithoutdegree}
+%D Old stuff:
+
+% \def\rootradical{\Uroot    \defaultmathfamily "221A } % can be done in char-def
+% \def\surdradical{\Uradical \defaultmathfamily "221A } % can be done in char-def
+
+\def\root#1\of{\rootradical{#1}} % #2
+
+\unexpanded\def\sqrt{\doifnextoptionalelse\rootwithdegree\rootwithoutdegree}
+
+\def\rootwithdegree[#1]{\rootradical{#1}}
+\def\rootwithoutdegree {\rootradical  {}}
+
+%D Even older stuff:
+
+% % is now a ordinary character
 %
-% \def\rootwithdegree   [#1]{\rootradical{#1}}
-% \def\rootwithoutdegree    {\rootradical  {}}
+% \let\normalsurd\surd % \Uradical "0 "221A
+% \unexpanded\def\surd{\normalsurd{}}
+
+
+%D The real thing:
 
 \installcorenamespace{mathradical}
 \installcorenamespace{mathradicalalternative}
diff --git a/tex/context/base/math-stc.mkvi b/tex/context/base/math-stc.mkvi
index 4652ee564..dd74f494c 100644
--- a/tex/context/base/math-stc.mkvi
+++ b/tex/context/base/math-stc.mkvi
@@ -265,7 +265,6 @@
    \edef\currentmathstackers{#category}%
    \mathstackersparameter\c!left\relax
    \ifmmode\math_class_by_parameter\mathstackersparameter\else\dontleavehmode\fi
-%    \ifmmode\mathrel\else\dontleavehmode\fi
      {\edef\p_offset     {\mathstackersparameter\c!offset}%
       \edef\p_location   {\mathstackersparameter\c!location}%
       \edef\p_order      {\mathstackersparameter\c!order}%
@@ -890,6 +889,40 @@
 % \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}}
diff --git a/tex/context/base/mult-de.mkii b/tex/context/base/mult-de.mkii
index 4b7a54e61..4ac85404b 100644
--- a/tex/context/base/mult-de.mkii
+++ b/tex/context/base/mult-de.mkii
@@ -822,6 +822,7 @@
 \setinterfaceconstant{mindepth}{mindepth}
 \setinterfaceconstant{minheight}{minhoehe}
 \setinterfaceconstant{minwidth}{minbreite}
+\setinterfaceconstant{moffset}{moffset}
 \setinterfaceconstant{monthconversion}{monthconversion}
 \setinterfaceconstant{more}{more}
 \setinterfaceconstant{mpdepth}{mpdepth}
diff --git a/tex/context/base/mult-def.lua b/tex/context/base/mult-def.lua
index 07e1139f0..9398733bc 100644
--- a/tex/context/base/mult-def.lua
+++ b/tex/context/base/mult-def.lua
@@ -8932,6 +8932,16 @@ return {
    ["pe"]="کمترین‌عرض",
    ["ro"]="latimeminima",
   },
+  ["moffset"]={
+   ["cs"]="moffset",
+   ["de"]="moffset",
+   ["en"]="moffset",
+   ["fr"]="moffset",
+   ["it"]="moffset",
+   ["nl"]="moffset",
+   ["pe"]="moffset",
+   ["ro"]="moffset",
+  },
   ["mpwidth"]={
    ["en"]="mpwidth",
    ["nl"]="mpbreedte",
diff --git a/tex/context/base/mult-en.mkii b/tex/context/base/mult-en.mkii
index 7b06ec627..aee58f9b5 100644
--- a/tex/context/base/mult-en.mkii
+++ b/tex/context/base/mult-en.mkii
@@ -822,6 +822,7 @@
 \setinterfaceconstant{mindepth}{mindepth}
 \setinterfaceconstant{minheight}{minheight}
 \setinterfaceconstant{minwidth}{minwidth}
+\setinterfaceconstant{moffset}{moffset}
 \setinterfaceconstant{monthconversion}{monthconversion}
 \setinterfaceconstant{more}{more}
 \setinterfaceconstant{mpdepth}{mpdepth}
diff --git a/tex/context/base/mult-fr.mkii b/tex/context/base/mult-fr.mkii
index 55aa3af79..fff2def29 100644
--- a/tex/context/base/mult-fr.mkii
+++ b/tex/context/base/mult-fr.mkii
@@ -822,6 +822,7 @@
 \setinterfaceconstant{mindepth}{profondeurmin}
 \setinterfaceconstant{minheight}{hauteurmin}
 \setinterfaceconstant{minwidth}{largeurmin}
+\setinterfaceconstant{moffset}{moffset}
 \setinterfaceconstant{monthconversion}{monthconversion}
 \setinterfaceconstant{more}{more}
 \setinterfaceconstant{mpdepth}{mpdepth}
diff --git a/tex/context/base/mult-it.mkii b/tex/context/base/mult-it.mkii
index 6d3591c04..140c12198 100644
--- a/tex/context/base/mult-it.mkii
+++ b/tex/context/base/mult-it.mkii
@@ -822,6 +822,7 @@
 \setinterfaceconstant{mindepth}{mindeoth}
 \setinterfaceconstant{minheight}{altezzamin}
 \setinterfaceconstant{minwidth}{ampiezzamin}
+\setinterfaceconstant{moffset}{moffset}
 \setinterfaceconstant{monthconversion}{monthconversion}
 \setinterfaceconstant{more}{more}
 \setinterfaceconstant{mpdepth}{mpdepth}
diff --git a/tex/context/base/mult-mps.lua b/tex/context/base/mult-mps.lua
index 59411cd97..48fe36b52 100644
--- a/tex/context/base/mult-mps.lua
+++ b/tex/context/base/mult-mps.lua
@@ -55,7 +55,7 @@ return {
         "colormodel",  "graypart",
         "dashpart", "penpart",
 --         "colorpart",
-        "stroked", "filled", "textual", "clipped", "bounded",
+        "stroked", "filled", "textual", "clipped", "bounded", "pathpart",
         "expandafter",
     },
     commands = {
diff --git a/tex/context/base/mult-nl.mkii b/tex/context/base/mult-nl.mkii
index 275f86c1a..0624b01bf 100644
--- a/tex/context/base/mult-nl.mkii
+++ b/tex/context/base/mult-nl.mkii
@@ -822,6 +822,7 @@
 \setinterfaceconstant{mindepth}{mindiepte}
 \setinterfaceconstant{minheight}{minhoogte}
 \setinterfaceconstant{minwidth}{minbreedte}
+\setinterfaceconstant{moffset}{moffset}
 \setinterfaceconstant{monthconversion}{maandconversie}
 \setinterfaceconstant{more}{meer}
 \setinterfaceconstant{mpdepth}{mpdiepte}
diff --git a/tex/context/base/mult-pe.mkii b/tex/context/base/mult-pe.mkii
index cff5dfce4..857a46cac 100644
--- a/tex/context/base/mult-pe.mkii
+++ b/tex/context/base/mult-pe.mkii
@@ -822,6 +822,7 @@
 \setinterfaceconstant{mindepth}{کمترین‌عمق}
 \setinterfaceconstant{minheight}{کمترین‌ارتفاع}
 \setinterfaceconstant{minwidth}{کمترین‌عرض}
+\setinterfaceconstant{moffset}{moffset}
 \setinterfaceconstant{monthconversion}{monthconversion}
 \setinterfaceconstant{more}{more}
 \setinterfaceconstant{mpdepth}{mpdepth}
diff --git a/tex/context/base/mult-ro.mkii b/tex/context/base/mult-ro.mkii
index e901e28f4..e73e59962 100644
--- a/tex/context/base/mult-ro.mkii
+++ b/tex/context/base/mult-ro.mkii
@@ -822,6 +822,7 @@
 \setinterfaceconstant{mindepth}{mindepth}
 \setinterfaceconstant{minheight}{inaltimeminima}
 \setinterfaceconstant{minwidth}{latimeminima}
+\setinterfaceconstant{moffset}{moffset}
 \setinterfaceconstant{monthconversion}{monthconversion}
 \setinterfaceconstant{more}{more}
 \setinterfaceconstant{mpdepth}{mpdepth}
diff --git a/tex/context/base/status-files.pdf b/tex/context/base/status-files.pdf
index 8f9abcd1a..f032aa51f 100644
--- a/tex/context/base/status-files.pdf
+++ b/tex/context/base/status-files.pdf
diff --git a/tex/context/base/status-lua.log b/tex/context/base/status-lua.log
index 838cc2383..f8901d762 100644
--- a/tex/context/base/status-lua.log
+++ b/tex/context/base/status-lua.log
@@ -1,6 +1,6 @@
 (cont-yes.mkiv
 
-ConTeXt  ver: 2013.08.17 00:58 MKIV beta  fmt: 2013.8.17  int: english/english
+ConTeXt  ver: 2013.08.20 12:31 MKIV beta  fmt: 2013.8.20  int: english/english
 
 system          > 'cont-new.mkiv' loaded
 (cont-new.mkiv)
diff --git a/tex/context/base/status-mkiv.lua b/tex/context/base/status-mkiv.lua
index 62bfc790c..6901db4cc 100644
--- a/tex/context/base/status-mkiv.lua
+++ b/tex/context/base/status-mkiv.lua
@@ -1857,6 +1857,12 @@ return {
   },
   {
    category = "mkiv",
+   filename = "math-rad",
+   loading  = "always",
+   status   = "okay",
+  },
+  {
+   category = "mkiv",
    comment  = "code might move to here",
    filename = "math-inl",
    loading  = "always",
diff --git a/tex/context/interface/keys-cs.xml b/tex/context/interface/keys-cs.xml
index f7de67072..122bd7a22 100644
--- a/tex/context/interface/keys-cs.xml
+++ b/tex/context/interface/keys-cs.xml
@@ -828,6 +828,7 @@
 		<cd:constant name='mindepth' value='mindepth'/>
 		<cd:constant name='minheight' value='minvyska'/>
 		<cd:constant name='minwidth' value='minsirka'/>
+		<cd:constant name='moffset' value='moffset'/>
 		<cd:constant name='monthconversion' value='monthconversion'/>
 		<cd:constant name='more' value='more'/>
 		<cd:constant name='mpdepth' value='mpdepth'/>
diff --git a/tex/context/interface/keys-de.xml b/tex/context/interface/keys-de.xml
index 07add1d02..a024e918f 100644
--- a/tex/context/interface/keys-de.xml
+++ b/tex/context/interface/keys-de.xml
@@ -828,6 +828,7 @@
 		<cd:constant name='mindepth' value='mindepth'/>
 		<cd:constant name='minheight' value='minhoehe'/>
 		<cd:constant name='minwidth' value='minbreite'/>
+		<cd:constant name='moffset' value='moffset'/>
 		<cd:constant name='monthconversion' value='monthconversion'/>
 		<cd:constant name='more' value='more'/>
 		<cd:constant name='mpdepth' value='mpdepth'/>
diff --git a/tex/context/interface/keys-en.xml b/tex/context/interface/keys-en.xml
index 954dcffd2..8e4ef2561 100644
--- a/tex/context/interface/keys-en.xml
+++ b/tex/context/interface/keys-en.xml
@@ -828,6 +828,7 @@
 		<cd:constant name='mindepth' value='mindepth'/>
 		<cd:constant name='minheight' value='minheight'/>
 		<cd:constant name='minwidth' value='minwidth'/>
+		<cd:constant name='moffset' value='moffset'/>
 		<cd:constant name='monthconversion' value='monthconversion'/>
 		<cd:constant name='more' value='more'/>
 		<cd:constant name='mpdepth' value='mpdepth'/>
diff --git a/tex/context/interface/keys-fr.xml b/tex/context/interface/keys-fr.xml
index b71707d8f..db2719fe6 100644
--- a/tex/context/interface/keys-fr.xml
+++ b/tex/context/interface/keys-fr.xml
@@ -828,6 +828,7 @@
 		<cd:constant name='mindepth' value='profondeurmin'/>
 		<cd:constant name='minheight' value='hauteurmin'/>
 		<cd:constant name='minwidth' value='largeurmin'/>
+		<cd:constant name='moffset' value='moffset'/>
 		<cd:constant name='monthconversion' value='monthconversion'/>
 		<cd:constant name='more' value='more'/>
 		<cd:constant name='mpdepth' value='mpdepth'/>
diff --git a/tex/context/interface/keys-it.xml b/tex/context/interface/keys-it.xml
index ffdc8e2a6..eadd1ca4b 100644
--- a/tex/context/interface/keys-it.xml
+++ b/tex/context/interface/keys-it.xml
@@ -828,6 +828,7 @@
 		<cd:constant name='mindepth' value='mindeoth'/>
 		<cd:constant name='minheight' value='altezzamin'/>
 		<cd:constant name='minwidth' value='ampiezzamin'/>
+		<cd:constant name='moffset' value='moffset'/>
 		<cd:constant name='monthconversion' value='monthconversion'/>
 		<cd:constant name='more' value='more'/>
 		<cd:constant name='mpdepth' value='mpdepth'/>
diff --git a/tex/context/interface/keys-nl.xml b/tex/context/interface/keys-nl.xml
index b09d73183..37b7c6213 100644
--- a/tex/context/interface/keys-nl.xml
+++ b/tex/context/interface/keys-nl.xml
@@ -828,6 +828,7 @@
 		<cd:constant name='mindepth' value='mindiepte'/>
 		<cd:constant name='minheight' value='minhoogte'/>
 		<cd:constant name='minwidth' value='minbreedte'/>
+		<cd:constant name='moffset' value='moffset'/>
 		<cd:constant name='monthconversion' value='maandconversie'/>
 		<cd:constant name='more' value='meer'/>
 		<cd:constant name='mpdepth' value='mpdiepte'/>
diff --git a/tex/context/interface/keys-pe.xml b/tex/context/interface/keys-pe.xml
index 069de9a1f..a517697e3 100644
--- a/tex/context/interface/keys-pe.xml
+++ b/tex/context/interface/keys-pe.xml
@@ -828,6 +828,7 @@
 		<cd:constant name='mindepth' value='کمترین‌عمق'/>
 		<cd:constant name='minheight' value='کمترین‌ارتفاع'/>
 		<cd:constant name='minwidth' value='کمترین‌عرض'/>
+		<cd:constant name='moffset' value='moffset'/>
 		<cd:constant name='monthconversion' value='monthconversion'/>
 		<cd:constant name='more' value='more'/>
 		<cd:constant name='mpdepth' value='mpdepth'/>
diff --git a/tex/context/interface/keys-ro.xml b/tex/context/interface/keys-ro.xml
index b16f25e2c..d5935e6e5 100644
--- a/tex/context/interface/keys-ro.xml
+++ b/tex/context/interface/keys-ro.xml
@@ -828,6 +828,7 @@
 		<cd:constant name='mindepth' value='mindepth'/>
 		<cd:constant name='minheight' value='inaltimeminima'/>
 		<cd:constant name='minwidth' value='latimeminima'/>
+		<cd:constant name='moffset' value='moffset'/>
 		<cd:constant name='monthconversion' value='monthconversion'/>
 		<cd:constant name='more' value='more'/>
 		<cd:constant name='mpdepth' value='mpdepth'/>
diff --git a/tex/generic/context/luatex/luatex-fonts-merged.lua b/tex/generic/context/luatex/luatex-fonts-merged.lua
index d2d3b3d83..8e883bf9a 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 : luatex-fonts-merged.lua
 -- parent file : luatex-fonts.lua
--- merge date  : 08/17/13 00:58:38
+-- merge date  : 08/20/13 12:31:41
 
 do -- begin closure to overcome local limits and interference
 
@@ -3802,7 +3802,7 @@ function constructors.scale(tfmdata,specification)
   end
   target.type=isvirtual and "virtual" or "real"
   target.postprocessors=tfmdata.postprocessors
-  local targetslant=(parameters.slant     or parameters[1] or 0)
+  local targetslant=(parameters.slant     or parameters[1] or 0) 
   local targetspace=(parameters.space     or parameters[2] or 0)*hdelta
   local targetspace_stretch=(parameters.space_stretch or parameters[3] or 0)*hdelta
   local targetspace_shrink=(parameters.space_shrink or parameters[4] or 0)*hdelta