%D \module
%D   [       file=x-mathml,
%D        version=2008.05.29,
%D          title=\CONTEXT\ XML Modules,
%D       subtitle=Loading \MATHML\ Filters,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE / Hans Hagen \& Ton Otten}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

% \xmlfilter{#1}{/*/name()} -> \xmltag

% This module is under construction and will be cleaned up.

\writestatus{loading}{ConTeXt XML Macros / MathML Renderer}

\unprotect

\startmodule [mathml]

\ctxloadluafile{x-mathml}{}

\startxmlsetups xml:mml:define
    \xmlsetsetup{\xmldocument} {(formula|subformula)} {mml:formula}
    \xmlfilter  {\xmldocument} {omt:*/function(remapopenmath)}
    \xmlfilter  {\xmldocument} {mml:bind/function(remapmmlbind)}
    \xmlfilter  {\xmldocument} {mml:csymbol/function(remapmmlcsymbol)}
    \xmlsetsetup{\xmldocument} {mml:*} {mml:*}
    \xmlsetsetup{\xmldocument} {mml:apply/mml:apply/mml:inverse/../../..} {mml:apply:inverse}
    \xmlstrip   {\xmldocument} {(mml:mi|mml:mo|mml:mn|mml:mtext|mml:csymbol)}
\stopxmlsetups

\xmlregisterns{omt}{openmath}
\xmlregisterns{mml}{mathml}

\xmlregistersetup{xml:mml:define}

\unexpanded\def\setupMMLappearance[#1]{\dodoubleargument\getparameters[@@MML#1]}

\def\MMLhack{\let\MMLpar\par \let\par\relax \everyvbox{\let\par\MMLpar}}

\xmlmapvalue {mml:math:mode} {display} {\displaymathematics}
\xmlmapvalue {mml:math:mode} {inline}  {\inlinemathematics}

\startxmlsetups mml:math
    \xmlval{mml:math:mode}{\xmlatt{#1}{mode}}{\automathematics}{\MMLhack\xmlflush{#1}}
\stopxmlsetups

\startxmlsetups mml:imath
    \inlinemathematics{\MMLhack\xmlflush{#1}}
\stopxmlsetups

\startxmlsetups mml:dmath
    \displaymathematics{\MMLhack\xmlflush{#1}}
\stopxmlsetups

%D First we define some general formula elements.

\startxmlsetups mml:formula
    \edef\mmlformulalabel   {\xmlatt{#1}{label}\xmlatt{#1}{id}}
    \edef\mmlformulasublabel{\xmlatt{#1}{sublabel}\xmlatt{#1}{id}}
    \doifsomething\mmlformulalabel{\placeformula[\mmlformulalabel]{\mmlformulasublabel}}
    \startformula\MMLhack\xmlfirst{#1}{/mml:math}\stopformula
\stopxmlsetups

\setfalse\mmlignoredelimiter
\settrue \mmlsomeleftdelimiter

\def\MMLleftorright
   {\ifconditional\mmlsomeleftdelimiter
      \setfalse\mmlsomeleftdelimiter\expandafter\MMLleft
    \else
      \settrue \mmlsomeleftdelimiter\expandafter\MMLright
    \fi}

\ifx\MMLleft  \undefined \let\MMLleft  \firstofoneargument \fi
\ifx\MMLright \undefined \let\MMLright \firstofoneargument \fi
\ifx\MMLmiddle\undefined \let\MMLmiddle\firstofoneargument \fi

\def\mmlleftdelimiter       #1{\ifconditional\mmlignoredelimiter#1\else\normalordelimiter{#1}{\MMLleft       #1}\fi}
\def\mmlrightdelimiter      #1{\ifconditional\mmlignoredelimiter#1\else\normalordelimiter{#1}{\MMLright      #1}\fi}
\def\mmlmiddledelimiter     #1{\ifconditional\mmlignoredelimiter#1\else\normalordelimiter{#1}{\MMLmiddle     #1}\fi}
\def\mmlleftorrightdelimiter#1{\ifconditional\mmlignoredelimiter#1\else\normalordelimiter{#1}{\MMLleftorright#1}\fi}

\def\mmlchar#1{\char#1 } % used in lua code

% \newcount\delimiternesting \appendtoks \delimiternesting\zerocount \to \everymathematics

% \def\mmlleftdelimiter  #1{\ifconditional\mmlignoredelimiter#1\else\normalordelimiter{#1}{%
% \advance\delimiternesting\plusone \MMLleft  #1}\fi}
% \def\mmlrightdelimiter #1{\ifconditional\mmlignoredelimiter#1\else\normalordelimiter{#1}{%
% \advance\delimiternesting\plusone \MMLright#1}\fi}
% \def\mmlmiddledelimiter#1{\ifconditional\mmlignoredelimiter#1\else\normalordelimiter{#1}{%
% \ifcase\delimiternesting\MMLleft\else\MMLmiddle\fi#1}\fi}


%D Remark: from now on this is a module and no longer an xtag
%D filter. There is an intermediate cleaner module but it has
%D some namespace limitations. Here we do it the \MKIV\ way.

\def\widevec#1%
  {\vbox{\mathsurround\zeropoint\ialign{##\crcr
     \rightarrowfill\crcr\noalign{\nointerlineskip}%
      $\hfil\displaystyle{#1}\hfil$\crcr}}}

%D The rendering macros:

\def\MMLrm{\mr}

\def\MMLseparator#1{\removeunwantedspaces{#1}\ignorespaces} % nils space after separator
\def\MMLseparator#1{,} % todo, for europe we need to block the space

%D Since I only had the draft of MathML 2 and later 3 as example of
%D rendering, there are probably a lot of omissions and
%D misinterpretations. At least I learned some bits and
%D pieces of math rendering.
%D
%D The main complications were not so much the math, but to
%D find the most efficient way to handle elements without
%D spacing beging messed up. The first implementation was
%D aimed at getting reasonable output, this second
%D implementation is already better in terms of handling
%D nesting, and I will definitely need a third one that has
%D more efficient and less ugly code.
%D
%D The \TEX\ part is not that complicated and once the
%D preprocessor was okay, the rest way just a lot of keying
%D and testing. It all comes down to gobbling, redefining,
%D and not so much to parsing.
%D
%D The second implementation expanded the whole math sequence
%D into an internal \TEX\ representation. This is a rather clean
%D and fast process. Filtering and testing takes place by
%D redefining teh internal representation macros.
%D
%D The third implementation may look a bit more messy in some
%D respects. This is because in \TEX\ it's not that trivial to
%D implement a tree handler. We use a stack for the \type {apply}
%D element and other sequential content. Occasionally we need to
%D peek into child elements which involves messy code. This
%D implementation is closer to the normal \XML\ handling in
%D \CONTEXT.

%D We start with the parent elements and the option handler.

\def\xmlmathmldirective#1{\dosetvalue{MML#1}}

%def\xmlmathmldirective#1#2#3{[#1][#2][#3]\dosetvalue{MML#1}{#2}{#3}}

%D In the styles, options can be set with:

\unexpanded\def\setupMMLappearance[#1]{\dodoubleargument\getparameters[MML#1]} % no @@ because passed to lua

%D We will apply inner math to all bits and pieces made up by an
%D \type {apply}.

\def\MMLmathinner
  {\ifinner \expandafter \firstofoneargument \else \expandafter \mathinner \fi}

%D Auxiliary MathML macros: (to be generalized)

\def\mmlfirst  #1{\xmlelement{#1}{1}} % we can move these inline if needed
\def\mmlsecond #1{\xmlelement{#1}{2}}
\def\mmlthird  #1{\xmlelement{#1}{3}}
\def\mmlprelast#1{\xmlelement{#1}{-2}}
\def\mmllast   #1{\xmlelement{#1}{-1}}

\starttexdefinition doifelsemmlfunction #1
    \xmldoifelse {#1} {/mml:fn} {
        \firstoftwoarguments
    } {
        \xmldoifelse {#1} {/mml:apply/mml:fn} {
            \firstoftwoarguments
        } {
            \xmldoifelse {#1} {/mml:ci[@type=='fn']} {
                \firstoftwoarguments
            } {
                \secondoftwoarguments
            }
        }
    }
\stoptexdefinition

%D Special features:

                \newtoks \@@postponedMMLactions \setfalse \somepostponedMMLactions

                \def\postponeMMLactions#1%
                  {\global\settrue\somepostponedMMLactions
                   \global\@@postponedMMLactions\expandafter{\the\@@postponedMMLactions#1}}

                \def\postponedMMLactions
                  {\global\setfalse\somepostponedMMLactions
                   \@EA\global\@EA\@@postponedMMLactions\@EA\emptytoks
                   \the\@@postponedMMLactions}

%D A couple of lists:

\convertargument
    mml:times|mml:divide|mml:power|%
    mml:lt|mml:gt|mml:eq|mml:leq|mml:geq|%
    mml:in|mml:inverse|%
    mml:fn|%
    mml:floor|mml:ceiling|%
    mml:mean|%
    mml:selector|%
    mml:abs|mml:int|mml:limit|mml:sum|mml:product|%
    mml:outerproduct|mml:innerproduct|mml:scalarproduct%
\to \MMLcmainresetlist

\convertargument
    mml:sin|mml:arcsin|mml:sinh|mml:arcsinh|%
    mml:cos|mml:arccos|mml:cosh|mml:arccosh|%
    mml:tan|mml:arctan|mml:tanh|mml:arctanh|%
    mml:cot|mml:arccot|mml:coth|mml:arccoth|%
    mml:csc|mml:arccsc|mml:csch|mml:arccsch|%
    mml:sec|mml:arcsec|mml:sech|mml:arcsech|%
    mml:ln|mml:exp|mml:log|%
    mml:abs|mml:int|mml:limit|mml:sum|mml:product|%
    mml:fn%
\to \MMLcfunctionlist

\convertargument
    mml:sin|mml:arcsin|mml:sinh|mml:arcsinh|%
    mml:cos|mml:arccos|mml:cosh|mml:arccosh|%
    mml:tan|mml:arctan|mml:tanh|mml:arctanh|%
    mml:cot|mml:arccot|mml:coth|mml:arccoth|%
    mml:csc|mml:arccsc|mml:csch|mml:arccsch|%
    mml:sec|mml:arcsec|mml:sech|mml:arcsech|%
    mml:ln|mml:exp|mml:log|%
    mml:abs%
\to \MMLcpurefunctionlist

\convertargument
    mml:diff|mml:partialdiff|mml:root%
\to \MMLcconstructlist

%D We use inner and grouping (begin/end and no b/e) else we
%D get problems with 1/2(1+2) and alike (todo: ask taco).
%D
%D The problem with apply is that we need to take care of
%D several situations, like:
%D
%D \starttyping
%D <apply> <.../> ...
%D <apply> <fn> ...
%D <apply> <apply> <ci> ...
%D <apply> <apply> <fn> <ci> ...
%D \stoptyping
%D
%D Because we translated version 2 of this renderer into
%D version 3 the following definitions may be sub optimal or
%D more complex than actually needed.

% simple version

\newcount\@MMLlevel \def\MMLcreset{\@MMLlevel\zerocount}

\let\MMLctempresetlist\empty \def\setMMLcreset{\edef\MMLctempresetlist}

\let\MMLdoL\donothing
\let\MMLdoR\donothing

\newcount\mmlapplydepth \def\MMLcreset{\mmlapplydepth\zerocount}

\startxmlsetups mml:apply
    \MMLmathinner {
        \xmldoif {#1} {/(\MMLcmainresetlist\string|\MMLctempresetlist)} {
    %     \MMLcreset
        }
        \edef\mmlapplyopentoken {\xmlatt{#1}{open}}
        \edef\mmlapplyclosetoken{\xmlatt{#1}{close}}
        \ifcase\mmlapplydepth \else
            \ifx\mmlapplyopentoken\empty
                \def\mmlapplyopentoken {(}
                \def\mmlapplyclosetoken{)}
            \fi
        \fi
        \advance\mmlapplydepth\plusone
        \begingroup
        \ifx\mmlapplyopentoken\empty
           \let\MMLdoL\donothing
           \let\MMLdoR\donothing
        \else
           \edef\MMLdoL{\noexpand\left \mmlapplyopentoken }
           \edef\MMLdoR{\noexpand\right\mmlapplyclosetoken}
        \fi
        \let\MMLctempresetlist\empty
        \xmldoifelse {#1} {/mml:apply} {
%             % <apply> <apply> ... </apply> <ci> .. </ci> </apply>
%             \xmldoifelse {#1} {/mml:apply(mml:plus|mml:minus)} {% [a]
%                 % yet incomplete and rather untested
%                 % <apply> <apply> <minus/> <tan/> <cos/> </apply> <ci>x</ci> </apply>
            } {% [b]
%                 \MMLcreset
            }
%             \MMLdoL
%             \mmlfirst{#1}
%             \ifconditional\somepostponedMMLactions
%                 \postponedMMLactions
%             \else
%                 \left(\MMLcreset\mmlsecond{#1}\right)
%             \fi
%             \MMLdoR
%         } {
            \edef\mmlapplyaction{\xmlfilter{#1}{/*/name()}}
            \doifsetupselse {mml:apply:\mmlapplyaction} {
                \xmlsetup{#1}{mml:apply:\mmlapplyaction}
             } {
%                 \MMLdoL
                \xmlsetup{#1}{\xmlfilter{#1}{/*/name()}}
%                 \MMLdoR
             }
%         }
        \endgroup
        \advance\mmlapplydepth\minusone
      }
\stopxmlsetups

\startxmlsetups mml:apply:mml:apply
    \xmlflush{#1}
    \xmlall{#1}{../[position()>1]}
\stopxmlsetups

\startxmlsetups mml:apply:mml:fn
    \xmldoifelse {#1} {/mml:ci} {
        \edef\mmlfnci{\xmlcontent{#1}{/mml:ci}}% replaces \XMLfnoperator
        \doifsetupselse{mml:fn:\mmlfnci} { % was mmc:fn:...
            \xmlsetup{#1}{mml:fn:\mmlfnci} % \MMLdoL/MMLdoR to be handled in plugin
        } {
            \MMLcreset
            \MMLdoL
            \mmlfirst{#1}
            \ifnum\xmlcount{#1}>\plusone
                \negthinspace % not enough
                \left(\MMLcreset\xmlconcatrange{#1}{/*}{2}{}{\MMLseparator,}\right)
            \fi
            \MMLdoR
        }
    } {
        \MMLcreset
        \MMLdoL
        \xmlall{#1}{/*}
        \MMLdoR
    }
\stopxmlsetups

\startxmlsetups mml:apply:mml:csymbol
    \xmlsetup{#1}{mml:csymbol} % \MMLdoL/MMLdoR to be handled in plugin
\stopxmlsetups

\startxmlsetups mml:apply:mml:ci
    \xmlfirst{#1}{/mml:ci}
    \ifnum\xmlcount{#1}>\plusone
       \left(\MMLcreset\xmlconcatrange{#1}{/*}{2}{}{\MMLseparator,}\right)
    \fi
\stopxmlsetups

% reln

\startxmlsetups mml:reln
    \writestatus{XML}{MathML element "reln" is obsolete}
\stopxmlsetups

% fn

\startxmlsetups mmc:fn:\utfchar{"00B1} % plusminus ±
    \ifnum\xmlcount{#1}>\plustwo
        \MMLcreset
        \left(\xmlconcat{#1}{/*}{2}{}{\mmlfirst{#1}}\right)
    \else
        \mmlfirst{#1}
    \fi
\stopxmlsetups

\startxmlsetups mmc:fn:\utfchar{"2213} % minusplus
    \xmlsetup{#1}{mmc:fn:plusminus}
\stopxmlsetups

\startxmlsetups mmc:fn
    \begingroup
    \edef\mmlnoffn{\xmlcount{#1}}
    \ifnum\mmlnoffn>\plustwo
      \def\MMCfnleft {\left(}
      \def\MMCfnright{\right)}
    \else
      \let\MMCfnleft \relax
      \let\MMCfnright\relax
    \fi
    \xmldoifelse {#1} {/mml:ci} { % first
        \edef\mmlfnci{\xmlcontent{#1}{/mml:ci}}% replaces \XMLfnoperator
        \doifsetupselse{mml:fn:\mmlfnci} { % was mmc:fn:...
            \xmlsetup{#1}{mml:fn:\mmlfnci} % \MMLdoL/MMLdoR to be handled in plugin
        } {
            \MMLcreset
            \getXMLstackdata\plusone
        }
    } {
        \xmldoifelse {#1} {/mml:apply} { % first
            \xmldoifelse {#1} {/(mml:plus\string|mml:minus)} {
                \left(\mmlfirst{#1}\right)
            } {
                \mmlfirst{#1}
            }
            \ifnum\mmlnoffn>\plusone
                \left(\xmlall{#1}{/!mml:apply}\right)
            \fi
        } {
            \MMLcreset
            \negthinspace
            \MMCfnleft
            \ifnum\mmlnoffn=\plustwo,\fi
            \xmlconcat{#1}{/*}{2}{}{\MMLseparator,}
            \MMCfnright
        }
    }
    \endgroup
\stopxmlsetups

\startxmlsetups mmc:fn:apply % where used?
    \xmldoifelse {#1} {/mml:ci} { % first
        \edef\mmlfnci{\xmlcontent{#1}{/mml:ci}}% replaces \XMLfnoperator
        \doifsetupselse{mml:fn:\mmlfnci} { % was mmc:fn:...
            \xmlsetup{#1}{mml:fn:\mmlfnci} % \MMLdoL/MMLdoR to be handled in plugin
        } {
            \MMLcreset
            \mmlfirst{#1}
            \ifnum\xmlcount{#1}>\plusone
                \negthinspace
                \left(\MMLcreset\xmlconcat{#1}{2}{}{\MMLseparator,}\right)
            \fi
        }
    } {
        \endgroup
        \MMLcreset
        \mmlfirst{#1}
    }
\stopxmlsetups

%D The next definition provide a kind of plug-in mechanism (see
%D the open math extension module).

% http://www.publishers.com/somename

\starttexdefinition mmlapplycsymbol #1#2#3#4
    % #1=full url, #2=name, #3=encoding, #4=text
    \doifelse {#3} {text} {
        {\mr #4}
    } {
        \doifsetupselse {mml:csymbol:#1} {
            % full url
            \directsetup{mml:csymbol:#1}
        } {
            % somename (fallback)
            \doifsetupselse {mml:csymbol:#2} {
                \directsetup{mml:csymbol:#2}
            } {
                \xmlval{mmc:cs}{#3}{}% todo
            }
        }
    }
\stoptexdefinition

\startxmlsetups mml:csymbol
    \ctxlua{lxml.mml.csymbol("#1")}
\stopxmlsetups

\startxmlsetups mml:csymbol:cdots
    \cdots
\stopxmlsetups

% \startxmlsetups mml:csymbol:<url> \stopxmlsetups

%D Alternative b will convert periods into comma's:
%D
%D \startbuffer
%D \startXMLdata
%D <imath><apply><cn>1.23</cn></apply></imath>
%D <dmath><apply><cn>1.23</cn></apply></dmath>
%D \stopXMLdata
%D
%D \type{\setupMMLappearance[cn] [alternative=b]}
%D
%D \startXMLdata
%D <imath><apply><cn>1.23</cn></apply></imath>
%D <dmath><apply><cn>1.23</cn></apply></dmath>
%D \stopXMLdata
%D \stopbuffer
%D
%D \start \typebuffer \getbuffer \stop

\setupMMLappearance[cn]       [\c!alternative=\v!a]
\setupMMLappearance[polar]    [\c!alternative=\v!a]  % a|b|c
\setupMMLappearance[float]    [\c!symbol=\v!no]      % \v!yes|dot
\setupMMLappearance[enotation][\c!symbol=\v!no]      % \v!yes|dot
\setupMMLappearance[base]     [\c!symbol=\v!numbers] % digits|characters|text|no

\startxmlsetups mml:cs \xmlcommand{#1}{/}{mml:cs:\xmlattdef{#1}{type}{default}} \stopxmlsetups
\startxmlsetups mml:ci \xmlcommand{#1}{/}{mml:ci:\xmlattdef{#1}{type}{default}} \stopxmlsetups
\startxmlsetups mml:cn \xmlcommand{#1}{/}{mml:cn:\xmlattdef{#1}{type}{default}} \stopxmlsetups

% helpers cn

\startxmlsetups mml:cn:default
    \mathopnolimits{\xmlflush{#1}}
\stopxmlsetups

% helpers ci

\startxmlsetups mml:ci:default
    \xmlflush{#1}
\stopxmlsetups

\startxmlsetups mml:ci:set
    {\blackboard{\xmlflush{#1}}} % todo
\stopxmlsetups

\startxmlsetups mml:ci:vector
    \widevec{\xmlflush{#1}}
\stopxmlsetups

\startxmlsetups mml:ci:matrix
    {\bi\xmlflush{#1}}
\stopxmlsetups

\startxmlsetups mml:ci:function
    \xmlflush{#1}% \negthinspace
\stopxmlsetups

\startxmlsetups mml:ci:fn
    \xmlsetup{#1}{mml:ci:function}
\stopxmlsetups

\startxmlsetups mml:ci:complex-cartesian
    \xmlsetup{#1}{mml:cn:complex}
\stopxmlsetups

\startxmlsetups mml:ci:complex
    \xmlsetup{#1}{mml:cn:complex}
\stopxmlsetups

\startxmlsetups mml:ci:complex-polar
    \xmlsetup{#1}{mml:cn:polar}
\stopxmlsetups

\startxmlsetups mml:ci:polar
    \xmlsetup{#1}{mml:cn:polar}
\stopxmlsetups

% helpers ci

\startxmlsetups mml:cn:default
    \xmlflush{#1}
\stopxmlsetups

\startxmlsetups mml:cn:integer
    \edef\mmlintegerbase{\xmlattdef{#1}{base}{}}
    \ifx\mmlintegerbase\empty
        \xmlflush{#1}
    \else
        \doifelse \MMLbasesymbol \v!no {
            \MMLcCNbasedata{\xmlflush{#1}}
        } {
            \MMLcCNbasedata{\xmlflush{#1}}_{
                \hbox {$
                    \mr
                    \scriptscriptstyle
                    \processaction
                        [\MMLbasesymbol]
                        [\v!characters=>\MMLcCNbasestring BODH,
                               \v!text=>\MMLcCNbasestring{BIN}{OCT}{DEC}{HEX},
                            \s!unknown=>\mmlintegerbase]
                $}
            }
        }
    \fi
\stopxmlsetups

\def\MMLcCNbasedata#1%
  {\ifnum\mmlintegerbase>10 \relax{\mr#1}\else#1\fi}

\def\MMLcCNbasestring#1#2#3#4%
  {\ifnum\mmlintegerbase= 2 #1\else
   \ifnum\mmlintegerbase= 8 #2\else
   \ifnum\mmlintegerbase=10 #3\else
   \ifnum\mmlintegerbase=16 #4\else
         \mmlintegerbase      \fi\fi\fi\fi}

\startxmlsetups mml:cn:polar
    \xmlsetup{#1}{mml:cn:polar:\MMLpolaralternative}
\stopxmlsetups

\startxmlsetups mml:cn:polar:a
    \mathopnolimits{Polar}% ? ? ?
    \left(\xmlsnippet{#1}{1},\xmlsnippet{#1}{3}\right)
\stopxmlsetups

\startxmlsetups mml:cn:polar:b
%   {\mr e}^{\xmlsnippet{#1}{1}\mskip2mu\getXMLentity{imaginaryi}}
    {\mr e}^{\xmlsnippet{#1}{1}+\xmlsnippet{#1}{3}\thinspace{\mr i}}
\stopxmlsetups

\startxmlsetups mml:cn:polar:c
%   \exp\left(\xmlsnippet{#1}{1}\mskip2mu\getXMLentity{imaginaryi}\right)}
    \exp\left(\xmlsnippet{#1}{1}+\xmlsnippet{#1}{3}\thinspace\getXMLentity{imaginaryi}\right)
\stopxmlsetups

\startxmlsetups mml:cn:complex-polar
    \xmlsetup{#1}{mml:cn:polar}
\stopxmlsetups

\startxmlsetups mml:cn:complex % todo ( )
    \left(\xmlsnippet{#1}{1} + \xmlsnippet{#1}{3}\thinspace{\mr i}\right)
\stopxmlsetups

\startxmlsetups mml:cn:complex-cartesian
    \xmlsetup{#1}{mml:cn:complex}
\stopxmlsetups

\startxmlsetups mml:cn:float
    \doifelse \MMLfloatsymbol \v!no {
        % make sure that e shows up ok
        \mathopnolimits{\xmlflush{#1}}
    } {
        % we should ignore \entities !
        \edef\mmlfloatstring{\xmlflush{#1}}
        \splitstring\mmlfloatstring\at e\to\first\and\last
        \ifx\first\empty
            \mmlfloatstring
        \else\ifx\last\empty
            \mmlfloatstring
        \else
            \first
            \doifelse \MMLfloatsymbol {dot} \cdot \times
            10^{\last}
        \fi \fi
    }
\stopxmlsetups

\startxmlsetups mml:cn:real
    \xmlsetup{#1}{mml:cn:float}
\stopxmlsetups

\startxmlsetups mml:cn:e-notation
    \doifelse \MMLenotationsymbol \v!no {
        \xmlsnippet{#1}{1}
        \unskip\mathopnolimits{e}\ignorespaces
        \xmlsnippet{#1}{3}
    } {
        \xmlsnippet{#1}{1}
        \doifelse \MMLenotationsymbol {dot} \cdot
        \times10^{\xmlsnippet{#1}{3}}
    }
\stopxmlsetups

\startxmlsetups mml:cn:logical
    \mathopnolimits{\xmlflush{#1}}
\stopxmlsetups

\startxmlsetups mml:cn:rational
    \xmldoifelse {#1} {/mml:sep} {
        \frac
            {\xmlsnippet{#1}{1}}
            {\xmlsnippet{#1}{3}}
    } {
        \xmlflush{#1}
    }
\stopxmlsetups

% interval

\setupMMLappearance[interval][\c!alternative=\v!a,\c!separator={,}]

% when empty element, then it's an apply

\startxmlsetups mml:interval
    \xmldoifelseempty {#1} {} {
        % #1 == interval
        \let\mmlintervalfirst \mmlfirst
        \let\mmlintervalsecond\mmlsecond
        \xmlsetup{#1}{mml:interval:\xmlattdef{#1}{closure}{closed}}
    } {
        % #1 == apply
        \let\mmlintervalfirst \mmlsecond
        \let\mmlintervalsecond\mmlthird
        \xmlsetup{#1}{mml:interval:\xmlattributedef{#1}{/mml:interval}{closure}{closed}}
    }
\stopxmlsetups

\startxmlsetups mml:interval:closed
    \left[\mmlintervalfirst{#1}\MMLseparator\MMLintervalseparator\mmlintervalsecond{#1}\right]
\stopxmlsetups

\startxmlsetups mml:interval:open-closed
    \doifelse \MMLintervalalternative \v!b {
        \left<\mmlintervalfirst{#1}\MMLseparator\MMLintervalseparator\mmlintervalsecond{#1}\right]
     } {
        \left(\mmlintervalfirst{#1}\MMLseparator\MMLintervalseparator\mmlintervalsecond{#1}\right]
     }
\stopxmlsetups

\startxmlsetups mml:interval:closed-open
    \doifelse \MMLintervalalternative \v!b {
        \left[\mmlintervalfirst{#1}\MMLseparator\MMLintervalseparator\mmlintervalsecond{#1}\right>
     } {
        \left[\mmlintervalfirst{#1}\MMLseparator\MMLintervalseparator\mmlintervalsecond{#1}\right)
     }
\stopxmlsetups

\startxmlsetups mml:interval:open
    \doifelse \MMLintervalalternative \v!b {
        \left<\mmlintervalfirst{#1}\MMLseparator\MMLintervalseparator\mmlintervalsecond{#1}\right>
     } {
        \left(\mmlintervalfirst{#1}\MMLseparator\MMLintervalseparator\mmlintervalsecond{#1}\right)
     }
\stopxmlsetups

% inverse

\setfalse\xmlinversefunction

\startxmlsetups mml:apply:inverse
    \settrue\xmlinversefunction
    \xmlsetup{#1}{\xmlfilter{#1}{/mml:apply/*/name(1)}}
\stopxmlsetups

% condition

% maybe a fast \xmlnonfirst

% instead of the following we could do \xmlcontent{#1}{/mml:bvar} etc

\startxmlsetups mml:bvar     \xmlflush{#1} \stopxmlsetups
\startxmlsetups mml:lowlimit \xmlflush{#1} \stopxmlsetups
\startxmlsetups mml:uplimit  \xmlflush{#1} \stopxmlsetups
\startxmlsetups mml:degree   \xmlflush{#1} \stopxmlsetups
\startxmlsetups mml:logbase  \xmlflush{#1} \stopxmlsetups
\startxmlsetups mml:fn       \xmlflush{#1} \stopxmlsetups

\startxmlsetups mml:condition
%     \xmldoif {#1} {/mml:bvar} {
%         \xmlfirst{#1}{/mml:bvar}\mid
%     }
    \xmlall{#1}{/!(mml:condition\string|mml:bvar)}
\stopxmlsetups

% declare

\setupMMLappearance[declare][\c!state=\v!start]

\startxmlsetups mml:declare
    \doif \MMLdeclarestate \v!start {
        \mathopnolimits{declare}
        \mmlfirst{#1}
        \ifnum\xmlcount{#1}>\plusone
            \thickspace
            \mathopnolimits{as}
            \thickspace
        \fi
        \mmlsecond{#1}
    }
\stopxmlsetups

% lambda

\setupMMLappearance[lambda][\c!alternative=b]

\startxmlsetups mml:lambda
    \begingroup
    \doifelse \MMLlambdaalternative \v!a {
        \lambda\left(\xmlconcat{#1}{/!mml:lambda}{\MMLseparator,}\right)
    } {
        \ifnum\xmlcount{#1}{/mml:bvar}>\plusone
            \left(\xmlconcat{#1}{/mml:bvar}{\MMLseparator,}\right)
        \else
            \xmlfirst{#1}{/mml:bvar}
        \fi
        \mapsto
        \MMLcreset
        \xmlall{#1}{/!(mml:bvar|mml:lambda)}
    }
    \endgroup
\stopxmlsetups

% compose

\startxmlsetups mml:compose
    \begingroup
    \MMLcreset
%   \let\MMLcCIfunction\firstofoneargument % brrr ? ? ?
    \doifelsemmlfunction {#1} {
       \left(\xmlconcat{#1}{/!mml:compose}{\circ}\right)
    } {
       \xmlconcat{#1}{/!mml:compose}{\circ}
    }
    \endgroup
\stopxmlsetups

\startxmlsetups mml:image
    \mathopnolimits{image} \left( {\mr\xmlfilter{#1}{/!mml:image/tag()}} \right)
\stopxmlsetups

\setupMMLappearance[piece][\c!separator=]

\startxmlsetups mml:piecewise
    \processaction
         [\MMLpieceseparator]
         [    \v!yes=>\def\theMMLpieceseparator{,&},
               \v!no=>\def\theMMLpieceseparator{&},
          \s!default=>\def\theMMLpieceseparator{&},
          \s!unknown=>\def\theMMLpieceseparator{\,\,\hbox{\MMLpieceseparator}\,\,}]
    \cases{\xmlflush{#1}}
\stopxmlsetups

\startxmlsetups mml:piece
    \mmlfirst{#1}\theMMLpieceseparator\mathematics{\mmlsecond{#1}}\crcr
\stopxmlsetups

\startxmlsetups mml:otherwise
%     \xmlflush{#1}\MMLcPIECEseparator&{\mr otherwise}\crcr
    \xmlflush{#1}&{\mr otherwise}\crcr
\stopxmlsetups

% end of piece

\startxmlsetups mml:quotient
    \lfloor\mmlsecond{#1}/\mmlthird{#1}\rfloor
\stopxmlsetups

\startxmlsetups mml:factorial
    \xmlall{#1}{/!factorial}!
\stopxmlsetups

\setupMMLappearance [divide] [\c!level=\!!maxcard,\c!alternative=\v!a]

\newcount\mmldividelevel

\startxmlsetups mml:divide
    \advance\mmldividelevel\plusone
    \doifelse \MMLdividealternative \v!b {
        \mmlsecond{#1}/\mmlthird{#1}
    } {
        \ifnum \mmldividelevel > \MMLdividelevel \relax % threshold
            \mmlsecond{#1}/\mmlthird{#1}
        \else
            \MMLcreset
            \frac{\MMLcreset\mmlsecond{#1}}{\MMLcreset\mmlthird{#1}}
        \fi
    }
    \advance\mmldividelevel\minusone
\stopxmlsetups

% min max

\startxmlsetups mml:min \mathopnolimits{min} \xmlsetup{#1}{mml:minmax} \stopxmlsetups
\startxmlsetups mml:max \mathopnolimits{max} \xmlsetup{#1}{mml:minmax} \stopxmlsetups

\startxmlsetups mml:minmax
    \xmldoif {#1} {/mml:bvar} {
        {}_{\xmlfirst{#1}{/mml:bvar}}
    }
    \left\{
    \xmlconcat{#1}{/!(mml:bvar\string|mml:max\string|mml:min)}{\MMLseparator,}
    \right\}
\stopxmlsetups

% minus plus

\setupMMLappearance [plus] [\c!alternative=\v!a] % b = no sign -> 3 1/4
\setupMMLappearance [sign] [\c!reduction=\v!yes]

% alternative b -> geen sign

% branch needed, else (a-b) + (c-d) goes wrong
% reset check in case of (-x) + 37
% reset check in case of (-x) + 37

\newcount\mmlpluscounter

\startxmlsetups mml:plus
    \doifelse \MMLsignreduction \v!yes {
        \MMLdoL
        \xmlsetup{#1}{mml:plus:reset}
        \xmlcommand{#1}{/!mml:plus}{mml:plus:body}
        \MMLdoR
    } {
        \ifnum\xmlcount{#1}{/!mml:plus}=\plusone
            +\xmlfirst{#1}{/!mml:plus}
        \else
            \MMLdoL
            \xmlconcat{#1}{/!mml:plus}{+}
            \MMLdoR
        \fi
    }
\stopxmlsetups

\startxmlsetups mml:plus:reset
    \mmlpluscounter\zerocount
\stopxmlsetups

\startxmlsetups mml:plus:body
    \advance\mmlpluscounter\plusone
    \ifnum\mmlpluscounter>\plusone
        \xmldoifelse{#1}{/mml:minus} {
            \ifnum\xmlcount{#1}{/!mml:minus}>\plusone
                +
            \fi
        } {
            \doifelse {\xmlatt{#1}{type}} {rational} {
                % fraction
            } {
                +
            }
        }
    \fi
    \xmldirect{#1}
\stopxmlsetups

\newcount\mmlminuscounter

\startsetups mml:minus
    \doifelse \MMLsignreduction \v!yes {
        \ifnum\xmlcount{#1}{/!mml:minus}=\plusone
            -\xmlfirst{#1}{/!mml:minus}
        \else
            \MMLdoL
            \xmlsetup{#1}{mml:minus:reset}
            \xmlcommand{#1}{/!mml:minus}{mml:minus:body}
            \MMLdoR
        \fi
    } {
        \left( % \MMLdoL
        \ifnum\xmlcount{#1}{/!mml:minus}=\plusone
            -\xmlfirst{#1}{/!mml:minus}
        \else
            \xmlsetup{#1}{mml:minus:reset}
            \xmlcommand{#1}{/!mml:minus}{mml:minus:body}
        \fi
        \right) % \MMLdoR
    }
\stopsetups

\startxmlsetups mml:minus:reset
    \mmlminuscounter\zerocount
\stopxmlsetups

\startxmlsetups mml:minus:body
    % we can slso use concat here
    \advance\mmlminuscounter\plusone
    \ifnum\mmlminuscounter>\plusone
        -
    \fi
    \xmldirect{#1}
\stopxmlsetups

% power

\setupMMLappearance[power][\c!reduction=\v!yes]

\let\MMLpowerelement\empty

\startxmlsetups mml:power
    \xmldoifelse {#1} {/mml:apply}  {
        \doifelse \MMLpowerreduction \v!yes {
            \xmldoifelse {#1} {/mml:apply/(\MMLcfunctionlist)} {
                \gdef\MMLpowerelement{\mmlthird{#1}}% postpone, no xdef
                \MMLcreset\mmlsecond{#1}
            } {
                \left(\MMLcreset\mmlsecond{#1}\right)^{\MMLcreset\mmlthird{#1}}
            }
        } {
            \left(\MMLcreset\mmlsecond{#1}\right)^{\MMLcreset\mmlthird{#1}}
        }
    } {
        \mmlsecond{#1}^{\MMLcreset\mmlthird{#1}}
    }
\stopxmlsetups

% rem

\startxmlsetups mml:rem
    \xmlconcat{#1}{/!mml:rem}{\mathopnolimits{mod}}
\stopxmlsetups

\setupMMLappearance [times] [\c!symbol=\v!no,\c!auto=\v!yes] % new, auto catches cn cn cn

\startxmlsetups mml:times
    \setMMLcreset{\MMLcfunctionlist\string|\MMLcconstructlist}%
    \doifelse\MMLtimesauto\v!no {
        \let\MMLtimes@@symbol\MMLtimessymbol
    } {
        \xmldoifelse {#1} {/mml:cn[name(1) == 'mml:cn']} {% name(1) is next one
           \doifinsetelse\MMLtimessymbol{\v!yes,\v!no} {
                \let\MMLtimes@@symbol\v!yes
            } {
                \let\MMLtimes@@symbol\MMLtimessymbol
            }
        } {
            \let\MMLtimes@@symbol\MMLtimessymbol
        }
    }
    \doifelse\MMLtimes@@symbol\v!yes {
        \xmlconcat{#1}{/!mml:times}{\times}
    } {
        \doifelse\MMLtimes@@symbol{dot} {
            \xmlconcat{#1}{/!mml:times}{\cdot}
        } {
            \doifelse\MMLtimes@@symbol{times} {
                \xmlconcat{#1}{/!mml:times}{\times}
            } {
                \xmlall{#1}{/!mml:times}
            }
        }
    }
\stopxmlsetups

\setupMMLappearance[root][\c!symbol=\v!yes]

\startxmlsetups mml:root
    \xmldoifelse {#1} {/mml:degree} {
        \root
            \doifnot\MMLrootsymbol\v!no{\MMLcreset\xmltext{#1}{/mml:degree}}
        \of
    } {
        \sqrt
    }
        {\MMLcreset\xmlall{#1}{/!(mml:degree\string|mml:root)}}
\stopxmlsetups

% gcd

\startxmlsetups mml:gcd
    \begingroup
        \gcd\left(\MMLcreset\xmlconcat{#1}{/!mml:gcd}{\MMLseparator,}\right)
    \endgroup
\stopxmlsetups

% and or xor implies, not

\startxmlsetups mml:and          \xmlconcat{#1}{/!mml:and}    {\wedge}               \stopxmlsetups
\startxmlsetups mml:or           \xmlconcat{#1}{/!mml:or}     {\vee}                 \stopxmlsetups
\startxmlsetups mml:xor          \xmlconcat{#1}{/!mml:xor}    {\mathopnolimits{xor}} \stopxmlsetups
\startxmlsetups mml:implies      \xmlconcat{#1}{/!mml:implies}{\Rightarrow}          \stopxmlsetups
\startxmlsetups mml:not     \neg \xmlall   {#1}{/!mml:not}                           \stopxmlsetups

% forall exists

%D We need to shift left below rotated A.

\startxmlsetups mml:forall
    \forall \negthinspace \xmlsetup{#1}{mml:forallexists}
\stopxmlsetups

\startxmlsetups mml:exists
    \exists \xmlsetup{#1}{mml:forallexists}
\stopxmlsetups

\def\mmlforallexistslist{mml:bvar\string|mml:forall\string|mml:exists\string|mml:condition}

\startxmlsetups mml:forallexists
    _{\xmlconcat{#1}{/mml:bvar}{\MMLseparator,}}
    \xmldoifelse {#1} {/mml:condition} {
        \thickspace
        \begingroup
            \xmlfirst{#1}{/mml:condition}
        \endgroup
        \ifcase\xmlcount{#1}{/!(\mmlforallexistslist)}\relax
            % nothing
        \or
            % == snelle volgende
            \left\vert
                \MMLcreset \medspace \xmlconcat{#1}{/!(\mmlforallexistslist)}{}
            \right.
        \else
            % special case
            \left\vert
                \matrix {
                    \xmlconcat{#1}{/!(\mmlforallexistslist)}{\hfill\crcr}
                }
            \right.
        \fi
    } {
        :\xmlfirst{#1}{/!(\mmlforallexistslist)}
    }
\stopxmlsetups

\startxmlsetups mml:abs
    \left\vert \MMLcreset\xmlall{#1}{/!mml:abs} \right\vert
\stopxmlsetups

\startxmlsetups mml:conjugate % watch extra {}
    {\overline{\MMLcreset\xmlall{#1}{/!mml:conjugate}}}
\stopxmlsetups

\startxmlsetups mml:arg
    \mathopnolimits{arg} \left( \MMLcreset\xmlall{#1}{/!mml:arg} \right)
\stopxmlsetups

\startxmlsetups mml:real
    \Re \left( \MMLcreset \xmlall{#1}{/!mml:real} \right)
\stopxmlsetups

\startxmlsetups mml:imaginary
    \Im \ left( \MMLcreset \xmlall{#1}{/!mml:imaginary} \right)
\stopxmlsetups

\startxmlsetups mml:lcm
    \mathopnolimits{lcm} \left( \xmlconcat{#1}{/!mml:lcm}{\MMLseparator,} \right)
\stopxmlsetups

\startxmlsetups mml:floor
    \lfloor \xmlall{#1}{/!mml:floor} \rfloor
\stopxmlsetups

\startxmlsetups mml:ceiling
    \lceiling \xmlall{#1}{/!mml:ceiling} \rceiling
\stopxmlsetups

% relations

% apply attr or eq

\setupMMLappearance[relation][\c!align=\v!no]

\xmlmapvalue {mml:relation} {mml:eq}         {=}
\xmlmapvalue {mml:relation} {mml:neq}        {\neq}
\xmlmapvalue {mml:relation} {mml:gt}         {>}
\xmlmapvalue {mml:relation} {mml:lt}         {<}
\xmlmapvalue {mml:relation} {mml:geq}        {\geq}
\xmlmapvalue {mml:relation} {mml:leq}        {\leq}
\xmlmapvalue {mml:relation} {mml:equivalent} {\equiv}
\xmlmapvalue {mml:relation} {mml:approx}     {\approx}
\xmlmapvalue {mml:relation} {mml:factorof}   {\mid}

\startxmlsetups mml:eq         \xmlsetup{#1}{mml:relation} \stopxmlsetups
\startxmlsetups mml:neq        \xmlsetup{#1}{mml:relation} \stopxmlsetups
\startxmlsetups mml:gt         \xmlsetup{#1}{mml:relation} \stopxmlsetups
\startxmlsetups mml:lt         \xmlsetup{#1}{mml:relation} \stopxmlsetups
\startxmlsetups mml:geq        \xmlsetup{#1}{mml:relation} \stopxmlsetups
\startxmlsetups mml:leq        \xmlsetup{#1}{mml:relation} \stopxmlsetups
\startxmlsetups mml:equivalent \xmlsetup{#1}{mml:relation} \stopxmlsetups
\startxmlsetups mml:approx     \xmlsetup{#1}{mml:relation} \stopxmlsetups
\startxmlsetups mml:factorof   \xmlsetup{#1}{mml:relation} \stopxmlsetups

\startxmlsetups mml:relation
    \edef\mmlapplyaction{\xmlfilter{#1}{/*/name()}}
    \MMLcreset \xmlsetup{#1}{mml:relation:\xmlattdef{#1}{align}{\MMLrelationalign}}
\stopxmlsetups

\startxmlsetups mml:relation:default
    \xmlconcatrange{#1}{/*}{2}{}{\xmlval{mml:relation}{\mmlapplyaction}{?}}
\stopxmlsetups
\startxmlsetups mml:relation:last
    \eqalign {
        \xmlconcatrange{#1}{/*}{2}{-2}{&\xmlval{mml:relation}{\mmlapplyaction}{?}\crcr}
        \mmlprelast{#1}&\xmlval{mml:relation}{\mmlapplyaction}{?}{}\mmllast{#1}
    }
\stopxmlsetups
\startxmlsetups mml:relation:first
    \eqalign {
        \mmlsecond{#1}\xmlval{mml:relation}{\mmlapplyaction}{?}{}
        &\xmlconcatrange{#1}{/*}{3}{}{\crcr\xmlval{mml:relation}{\mmlapplyaction}{?}{}&}
    }
\stopxmlsetups
\startxmlsetups mml:relation:left
    \eqalign {
        \xmlconcatrange{#1}{/*}{2}{}{&\xmlval{mml:relation}{\mmlapplyaction}{?}\crcr}
    }
\stopxmlsetups
\startxmlsetups mml:relation:right
    \eqalign {
        &\xmlconcatrange{#1}{/*}{2}{}{\crcr\xmlval{mml:relation}{\mmlapplyaction}{?}{}&}
    }
\stopxmlsetups
\startxmlsetups mml:relation:no
    \xmlsetup{#1}{mml:relation:default}
\stopxmlsetups
\startxmlsetups mml:relation:yes
    \xmlsetup{#1}{mml:relation:left}
\stopxmlsetups

% personal goody:

\edef\MMLcmainresetlist{\MMLcmainresetlist\string|becomes}

\xmlmapvalue {mml:relation} {mml:becomes} {:=}

\startxmlsetups mml:becomes \xmlsetup{#1}{mml:relation} \stopxmlsetups

% calculus and vector calculus

\startxmlsetups mml:domainofapplication
    \xmlall{#1}{/!mml:domainofapplication}
\stopxmlsetups

\setupMMLappearance[int][\c!location=\v!top]

\def\doMMLlimits#1{\doifelsevalue{MML#1\c!location}\v!top\limits\nolimits}

\startxmlsetups mml:int
    \MMLcreset
    \xmldoifelse {#1} {/mml:domainofapplication} {
        \int \doMMLlimits{int}_{\xmlfirst{#1}{/mml:domainofapplication}}\relax
    } {
        \xmldoifelse {#1} {/mml:condition} {
            \int \doMMLlimits{int}_{\xmlfirst{#1}{/mml:condition}}\relax
        } {
            \xmldoifelse {#1} {/mml:lowlimit} {
                \int \doMMLlimits{int}_{\xmlfirst{#1}{/mml:lowlimit}}^{\xmlfirst{#1}{/mml:uplimit}}
            } {
                % funny, why do we have lowlimit/uplimit then
                \xmldoifelse {#1} {/mml:apply/mml:interval} {
                    \int \doMMLlimits{int}_{\xmlindex{#1}{/mml:apply}{2}}^{\xmlindex{#1}{/mml:apply}{3}}
                } {
                    \int
                }
            }
        }
    }
    \MMLcreset
    \xmldoifelse {#1} {/mml:apply} {
        \doifelsemmlfunction {#1} { % todo test
            \xmlfirst{#1}{/mml:apply}
        } {
            % if there are too many () now, we need to be more clever
            \left( \xmlfirst{#1}{/mml:apply} \right)
        }
    } {
        \xmlfirst{#1}{/mml:ci}
    }
    \xmldoifelse {#1} {/mml:bvar} {
        \thinspace {\mr d} \xmlfirst{#1}{/mml:bvar}
    } {
        % nothing
    }
\stopxmlsetups

\setupMMLappearance[diff][\c!location=\v!top,\c!alternative=\v!a]

% \setupMMLappearance[diff][alternative=b]
%
% \startXMLdata
% <math><apply><apply><diff/><bvar><ci>x</ci></bvar><ci>f</ci></apply><ci>a</ci></apply></math>
% <math><apply><apply><diff/><bvar><ci>x</ci></bvar><degree>2</degree><ci>f</ci></apply><ci>a</ci></apply></math>
% \stopXMLdata

% d^y/dx^2
%
% \startXMLdata
% <math><apply><diff/>
%   <bvar><ci>x</ci><cn type="integer">2</cn></bvar>
%   <lambda><bvar><ci>x</ci></bvar><ci>y</ci></lambda>
% </apply></math>
% \stopXMLdata

\startxmlsetups mml:diff
   \MMLcreset
   \doifelse \MMLdiffalternative \v!a {
        \xmldoifelse {#1} {/mml:lambda} {
            % a special case (mathadore/openmath)
            \frac {
                d^{\xmlfirst{#1}{/mml:bvar}\xmlfirst{#1}{/mml:cn}}{\xmlfirst{#1}{/mml:lambda}\xmlfirst{#1}{/mml:ci}}
            } {
                d{\xmlfirst{#1}{/mml:bvar}\xmlfirst{#1}{/mml:ci}}^{\xmlfirst{#1}{/mml:bvar}\xmlfirst{#1}{/mml:cn}}
            }
        } {
            \xmldoifelse {#1} {/mml:bvar} {
                \frac {
                    {\mr d}{
                        \xmldoifelse {#1} {/mml:degree} {
                            ^{\xmlconcat{#1}{/mml:degree}\empty}
                        } {
                            \xmldoif {#1} {/mml:bvar/mml:degree} {
                                ^{\xmlconcat{#1}{/mml:bvar/mml:degree}+}
                            }
                        }
                    }
                    \doif \MMLdifflocation \v!top {
                        \xmldoifelse {#1} {/mml:ci} {
                            \xmlfirst{#1}{/mml:ci}
                        } {
                            \MMLcreset
                            \xmlfirst{#1}{/mml:apply}
                        }
                    }
                } {
                    {\mr d}
                    \xmlfirst{#1}{/mml:bvar/!mml:degree}
                    \xmldoif {#1} {/mml:bvar/mml:degree} {
                        ^{\xmlfirst{#1}{/mml:bvar/mml:degree}}
                    }
                }
                \doifnot \MMLdifflocation \v!top {
                    \left(\MMLcreset\xmlfirst{#1}{/(mml:apply\string|mml:ci)}\right)
                }
            } {
                \xmlconcatrange{#1}{/*}{2}{}^\prime
            }
        }
    } {
        \MMLcreset
        \xmlfirst{#1}{/(mml:apply\string|mml:ci)}
        % there can be problems with nested diff's: ^^{} error
        % so we add an empty group here
        {}^
        {
            \xmldoifelse {#1} {/mml:degree} {
                \edef\mmldegree{\xmlfirst{#1}{/mml:degree/mml:cn}}
                \ifx\mmldegree\empty
                    % what to do here
                \else
                    \dorecurse\mmldegree\prime
                \fi
            } {
                \prime
            }
        }
    }
\stopxmlsetups

\startxmlsetups mml:partialdiff
    \xmldoifelse {#1} {/mml:list} {
        {\mr D}_{
            \begingroup
                \setfalse\mmllistdelimiters
                \xmlall{#1}{/mml:list}
            \endgroup
        }
        \xmlfirst{#1}{/(mml:apply\string|mml:reln\string|mml:ci\string|mml:cn)}
    } {
        \xmldoifelse {#1} {/mml:bvar} {
            \frac {
                {\mr d}^{
                    \xmldoifelse {#1} {/mml:degree} {
                        \xmlconcat{#1}{/mml:degree}\empty
                    } {
                        \xmlconcat{#1}{/mml:bvar/mml:degree}+
                    }
                }
                \MMLcreset
                \xmlfirst{#1}{/(mml:apply\string|mml:reln\string|mml:ci\string|mml:cn)}
            } {
                \xmldoif {#1}{/mml:bvar/!mml:degree} {
                    \xmlfirst{#1}{/mml:bvar/!mml:degree} \,
                }
                {\mr d}\xmlfirst{#1}{/(mml:apply\string|mml:reln\string|mml:ci\string|mml:cn)}
                \xmldoif {#1} {/mml:bvar/mml:degree} {
                    ^{\xmlfirst{#1}{/mml:bvar/mml:degree}}
                }
            }
        } {
            \xmlfirst{#1}{/(mml:apply\string|mml:reln\string|mml:ci\string|mml:cn)}
        }
    }
\stopxmlsetups

\startxmlsetups mml:divergence \mathopnolimits{div}      \xmlall{#1}{/!mml:divergence} \stopxmlsetups
\startxmlsetups mml:grad       \mathopnolimits{grad}     \xmlall{#1}{/!mml:grad}       \stopxmlsetups
\startxmlsetups mml:curl       \mathopnolimits{curl}     \xmlall{#1}{/!mml:curl}       \stopxmlsetups
\startxmlsetups mml:laplacian  \nabla^2                  \xmlall{#1}{/!mml:laplacian}  \stopxmlsetups
\startxmlsetups mml:ident      \mathopnolimits{identity} \xmlall{#1}{/!mml:ident}      \stopxmlsetups

\setupMMLappearance[domain]  [symbol=]
\setupMMLappearance[codomain][symbol=]

\startxmlsetups mml:domain
    \doifelsenothing \MMLdomainsymbol {
        \mathopnolimits{domain}\MMLcreset\xmlall{#1}{/!mml:domain}
    } {
        \MMLdomainsymbol_{\xmlall{#1}{/!mml:domain}}
    }
\stopxmlsetups

\startxmlsetups mml:codomain
    \doifelsenothing \MMLcodomainsymbol {
        \mathopnolimits{codomain}\MMLcreset\xmlall{#1}{/!mml:codomain}
    } {
        \MMLcodomainsymbol_{\xmlall{#1}{/!mml:codomain}}
    }
\stopxmlsetups

% theory of sets

\startxmlsetups mml:set
    \left\{
    \xmldoifelse {#1} {/mml:condition} {
        \xmlfirst{#1}{/mml:bvar}\,\middle\vert\,\xmlfirst{#1}{/mml:condition}
    } {
        \xmlconcat{#1}{/!mml:set}{\MMLseparator,}
    }
    \right\}
    \relax % needed
\stopxmlsetups

\settrue\mmllistdelimiters

\startxmlsetups mml:list
    \begingroup
        \ifconditional\mmllistdelimiters\left [\fi
        \begingroup
            \settrue\mmllistdelimiters
            \xmlconcat{#1}{/!mml:list}{\MMLseparator,}
        \endgroup
        \ifconditional\mmllistdelimiters\right]\fi
    \endgroup
\stopxmlsetups

\startxmlsetups mml:union       \mmlsecond{#1} \cup            \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:intersect   \mmlsecond{#1} \cap            \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:in          \mmlsecond{#1} \in             \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:notin       \mmlsecond{#1} {\not\in}       \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:subset      \mmlsecond{#1} \subset         \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:prsubset    \mmlsecond{#1} \subseteq       \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:notsubset   \mmlsecond{#1} {\not\subset}   \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:notprsubset \mmlsecond{#1} {\not\subseteq} \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:setdiff     \mmlsecond{#1} \setminus       \mmlthird{#1} \stopxmlsetups

\startxmlsetups mml:card
    \left\vert \xmlall{#1}{/!mml:card} \right\vert
\stopxmlsetups

\startxmlsetups mml:cartesianproduct
    \xmlconcat{#1}{/!mml:cartesianproduct}{\times}
\stopxmlsetups

% sequences and series

\setupMMLappearance[sum]    [\c!location=\v!top]
\setupMMLappearance[product][\c!location=\v!top]

\xmlmapvalue {mml:sumprod} {sum}     {\sum}
\xmlmapvalue {mml:sumprod} {product} {\prod}

\startxmlsetups mml:sum     \edef\mmlsumprodname{sum}     \xmlsetup{#1}{mml:sumprod} \stopxmlsetups
\startxmlsetups mml:product \edef\mmlsumprodname{product} \xmlsetup{#1}{mml:sumprod} \stopxmlsetups

\def\mmlstackedsubscripts#1%
  {\vbox
     {\baselineskip\zeropoint % hack, taco vragen
      \halign{$\scriptstyle\hss##\hss$\cr#1\crcr}}}

% unfinished

\startxmlsetups mml:sumprod
    \begingroup
    \xmldoifelse {#1} {/(mml:condition\string|mml:bvar\string|mml:lowlimit)} {
        \def\mmlsumprodlower{
            _{
                \xmldoifelse {#1} {/mml:condition} {
                    \mmlstackedsubscripts{\xmlconcat{#1}{/mml:condition}{\crcr}}
                } {
                    \xmldoif {#1} {/mml:bvar} {
                        \xmlfirst{#1}{/mml:bvar}
                        \xmldoif{#1}{/mml:lowlimit}{=}
                    }
                    \xmlfirst{#1}{/mml:lowlimit}
                }
            }
        }
    } {
        \let\mmlsumprodlower\empty
    }
    \xmldoifelse {#1} {/mml:uplimit} {
        \def\mmlsumprodupper{^{\xmlfirst{#1}{/mml:uplimit}}}
    } {
        \let\mmlsumprodupper\empty
    }
   \xmldoif {#1} {/mml:interval} { % open math converter gives this
        \edef\mmlintervalfrom{\xmlindex{#1}{/mml:interval}{1}}
        \edef\mmlintervalto  {\xmlindex{#1}{/mml:interval}{2}}
        \ifx \mmlintervalfrom \empty \else
            \def\mmlsumprodlower{_{\xmldoif{#1}{/mml:bvar}{\xmlfirst{#1}{/mml:bvar}{=}}\mmlintervalfrom}}
        \fi
        \ifx \mmlintervalto \empty \else
            \def\mmlsumprodupper{^{\mmlintervalto}}
        \fi
    }
    \MMLcreset
    \xmlval{mml:sumprod}{\mmlsumprodname}{}\doMMLlimits\mmlsumprodname\mmlsumprodupper\mmlsumprodlower
    \MMLcreset
    \xmldoifelse {#1} {/mml:lambda/mml:apply} {
        \xmlfirst{#1}{/mml:lambda/mml:apply}% a bit of open math conversion mess
    } {
        \xmlfirst{#1}{/(mml:apply\string|mml:lambda\string|mml:ci)}%
    }
    \endgroup
\stopxmlsetups

\setupMMLappearance[limit][\c!location=\v!top]

\startxmlsetups mml:limit
    \MMLcreset \lim
    \doMMLlimits {limit}_{
        \MMLcreset
        \xmldoifelse {#1} {/mml:condition} {
            \xmlfirst{#1}{/mml:condition}
        } {
            \xmldoif {#1} {/mml:bvar} {
                \xmlfirst{#1}{/mml:bvar}\rightarrow
            }
            \xmlfirst{#1}{/mml:lowlimit}
        }
    }
    \begingroup
        % a bit of open math conversion mess, lambda needed for openmath, ok?
        \MMLcreset
        \xmlfirst{#1}{/mml:lambda/mml:apply}
        \xmlfirst{#1}{/(mml:apply\string|mml:lambda)}
    \endgroup
\stopxmlsetups

% consider a faster index

\startxmlsetups mml:tendsto
    \MMLcreset \mmlsecond{#1}
    \xmlval {mml:tendsto:type} {\xmlattdef{#1}{type}{default}} {\rightarrow}
    \MMLcreset \mmlthird{#1}
\stopxmlsetups

\xmlmapvalue {mml:tendsto:type} {above}   {\downarrow}
\xmlmapvalue {mml:tendsto:type} {below}   {\uparrow}
\xmlmapvalue {mml:tendsto:type} {default} {\rightarrow}

% elementary classical functions

\setupMMLappearance[log][\c!location=\v!right]

\startxmlsetups mml:exp
%   {\mr e}^{\xmlfirst{#1}{/mml:apply\string|mml:reln\string|mml:ci\string|mml:cn}}
    {\mr e}^{\xmlfirst{#1}{/!mml:exp}}
\stopxmlsetups

\startxmlsetups mml:log
   \xmldoifelse {#1} {/mml:logbase} {
        \doifelse \MMLloglocation \v!left {
            \mathop {
                {}^{\xmlfirst{#1}{/mml:logbase}}\negthinspace\mathopnolimits{log}
            }
        } {
            \mathopnolimits{log}_{\xmlfirst{#1}{/mml:logbase}}
        }
%         \MMLcreset
        \xmlfirst{#1}{/(mml:apply\string|mml:reln\string|mml:ci\string|mml:cn)}
%         \xmlsetup{#1}{mml:function} % todo, we start elsewhere
%         \mmlthird{#1}
    } {
        \mathopnolimits{log}
%         \MMLcreset
%         \xmlsetup{#1}{mml:function} % todo, we start elsewhere
            \xmlfirst{#1}{/(mml:apply\string|mml:reln\string|mml:ci\string|mml:cn)}
%         \mmlsecond{#1}
    }
\stopxmlsetups

\startxmlsetups mml:ln
    \mathopnolimits{ln}
    \xmlsetup{#1}{mml:function}
\stopxmlsetups

% statistics

\startxmlsetups mml:mean     \overline                             {\mmlsecond{#1}}         \stopxmlsetups
\startxmlsetups mml:sdev     \sigma                 \left(\MMLcreset\mmlsecond{#1}\right)   \stopxmlsetups
\startxmlsetups mml:variance \sigma                 \left(\MMLcreset\mmlsecond{#1}\right)^2 \stopxmlsetups
\startxmlsetups mml:median   \mathopnolimits{median}\left(\MMLcreset\mmlsecond{#1}\right)   \stopxmlsetups
\startxmlsetups mml:mode     \mathopnolimits{mode}  \left(\MMLcreset\mmlsecond{#1}\right)   \stopxmlsetups

% moments

\startxmlsetups mml:moment
    \left\langle
        \xmlfirst{#1}{/(mml:apply\string|mml:reln\string|mml:ci\string|mml:cn)}^{\xmlfirst{#1}{/mml:degree}}
    \right\rangle
    \xmldoif {#1} {mml:momentabout} {
        _{\xmlfirst{#1}{mml:momentabout}}
    }
\stopxmlsetups

% linear algebra

\setupMMLappearance [vector] [\c!direction=\v!horizontal,\c!separator={,}]

\startxmlsetups mml:vector
    \begingroup
    \ifnum\xmlcount{#1}>\plusone
        \doifelse\MMLvectordirection\v!horizontal {
            \left(\xmlconcat{#1}{/*}{\MMLseparator\MMLvectorseparator}\right)
        } {
            \MMLcreset\left(\matrix{\xmlconcat{#1}{/*}{\MMLseparator\MMLvectorseparator}}\right)
        }
    \else
      \overrightarrow{\charhtstrut\mmlfirst{#1}}
    \fi
    \endgroup
\stopxmlsetups

\settrue\MMCdelmatrix % ( ) when true

\startxmlsetups mml:matrix
    \begingroup
    \MMLcreset
    \ifconditional\MMCdelmatrix
        \left(\matrix{\xmlcommand{#1}{/mml:matrixrow}{mml:matrixrow:do}}\right)
    \else
        \settrue\MMCdelmatrix
        \matrix{\xmlcommand{#1}{/mml:matrixrow}{mml:matrixrow:do}}
    \fi
    \endgroup
\stopxmlsetups

\startxmlsetups mml:matrixrow
    \begingroup
    \MMLcreset
    \left(\xmlsetup{#1}{mml:matrixrow:do}\right)
    \endgroup
\stopxmlsetups

\startxmlsetups mml:matrixrow:do
    \xmlconcat{#1}{/*}{&}\crcr
\stopxmlsetups

\startxmlsetups mml:determinant
    \begingroup
    \setfalse\MMCdelmatrix
    \left|\mmlsecond{#1}\right|
    \endgroup
\stopxmlsetups

\startxmlsetups mml:transpose
    \mmlsecond{#1}^{\mathopnolimits{T}}
\stopxmlsetups

\startxmlsetups mml:selector
    \MMLmathinner{\mmlsecond{#1}_{\MMLcreset\xmlconcatrange{#1}{/*}{3}{}{\MMLseparator,}}}
\stopxmlsetups

\startxmlsetups mml:vectorproduct \mmlsecond{#1}\times \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:scalarproduct \mmlsecond{#1}\cdot  \mmlthird{#1} \stopxmlsetups
\startxmlsetups mml:outerproduct  \mmlsecond{#1}\otimes\mmlthird{#1} \stopxmlsetups

% semantic mapping elements

\setupMMLappearance[semantics][\c!state=\v!start]

\startxmlsetups mml:semantics
    \doifelse\MMLsemanticsstate\v!start {
        \xmlall{#1}{/mml:annotation}
    } {
        \xmlall{#1}{/!mml:annotation}
    }
\stopxmlsetups

\usemodule[x][calcmath]
%usemodule[x][asciimath]

\startxmlsetups mml:annotation
    \xmldoifelse {#1} {.[oneof(@encoding,'TeX','tex','TEX','ConTeXt','context','CONTEXT','ctx')]} {
        \xmlflushcontext{#1}
    } {
        \xmldoifelse {#1} {.[oneof(@encoding,'calcmath','cm')]} {
            \expanded{\calcmath{\xmlflush{#1}}}
        } {
            \xmldoifelse {#1} {.[oneof(@encoding,'asciimath','am')]} {
                \ifdefined\asciimath
                    \expanded{\asciimath{\xmlflush{#1}}}
                \else
                    \hbox{\tt no am loaded}%
                \fi
            } {
                \xmlall{#1}{../!mml:annotation}
            }
        }
    }
\stopxmlsetups

\startxmlsetups mml:annotation-xml
    % maybe diagnostics
\stopxmlsetups

% misc

\startxmlsetups mml:integers       \integers              \stopxmlsetups
\startxmlsetups mml:reals          \reals                 \stopxmlsetups
\startxmlsetups mml:rationals      \rationals             \stopxmlsetups
\startxmlsetups mml:naturalnumbers \naturalnumbers        \stopxmlsetups
\startxmlsetups mml:complexes      \complexes             \stopxmlsetups
\startxmlsetups mml:primes         \primes                \stopxmlsetups
\startxmlsetups mml:exponentiale   \mathopnolimits{e}     \stopxmlsetups
\startxmlsetups mml:imaginaryi     \mathopnolimits{i}     \stopxmlsetups
\startxmlsetups mml:notanumber     \mathopnolimits{NaN}   \stopxmlsetups
\startxmlsetups mml:true           \mathopnolimits{true}  \stopxmlsetups
\startxmlsetups mml:false          \mathopnolimits{false} \stopxmlsetups
\startxmlsetups mml:emptyset       \mathopnolimits{\O}    \stopxmlsetups
\startxmlsetups mml:pi             \pi                    \stopxmlsetups
\startxmlsetups mml:eulergamma     \gamma                 \stopxmlsetups
\startxmlsetups mml:infinity       \infty                 \stopxmlsetups

% gonio functions

\setupMMLappearance[function][\c!reduction=\v!yes]

% todo: \mfunction which adapts itself when registered as command

% todo: \def\mmlcfunction#1#2{\mathopnolimits{#2}\xmlsetup{#1}{mml:function}}

\startxmlsetups  mml:sin     \mathopnolimits    {sin}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:sinh    \mathopnolimits   {sinh}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:cos     \mathopnolimits    {cos}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:cosh    \mathopnolimits   {cosh}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:tan     \mathopnolimits    {tan}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:tanh    \mathopnolimits   {tanh}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:cot     \mathopnolimits    {cot}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:coth    \mathopnolimits   {coth}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:csc     \mathopnolimits    {csc}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:csch    \mathopnolimits   {csch}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:sec     \mathopnolimits    {sec}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:sech    \mathopnolimits   {sech}\xmlsetup{#1}{mml:function} \stopxmlsetups

\startxmlsetups  mml:arcsin  \mathopnolimits {arcsin}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arcsinh \mathopnolimits{arcsinh}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arccos  \mathopnolimits {arccos}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arccosh \mathopnolimits{arccosh}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arctan  \mathopnolimits {arctan}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arctanh \mathopnolimits{arctanh}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arccot  \mathopnolimits {arccot}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arccoth \mathopnolimits{arccoth}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arccsc  \mathopnolimits {arccsc}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arccsch \mathopnolimits{arccsch}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arcsec  \mathopnolimits {arcsec}\xmlsetup{#1}{mml:function} \stopxmlsetups
\startxmlsetups  mml:arcsech \mathopnolimits{arcsech}\xmlsetup{#1}{mml:function} \stopxmlsetups

\startxmlsetups mml:function
    \ifx\MMLpowerelement\empty
        \ifconditional\xmlinversefunction^{-1}\fi
        \setfalse\xmlinversefunction
    \else
        ^{\ifconditional\xmlinversefunction-\fi\MMLpowerelement}
        \setfalse\xmlinversefunction
        \glet\MMLpowerelement\empty
    \fi
    \xmlsetup{#1}{mml:function:argument}
\stopxmlsetups

\startxmlsetups mml:function:argument
    \doifelse \MMLfunctionreduction \v!yes {
        \xmldoifelse {#1} {/mml:apply} {
            \xmldoifelse {#1} {/mml:apply/(\MMLcfunctionlist\string|mml:divide)}
                \donefalse
                \donetrue
        } {
            \donefalse
        }
    } {
        \donetrue
    }
    % beware, we still flush from 2 up
    \ifdone
        \left(
            \MMLcreset
            \xmlall{#1}{/[position()>1]}% \xmlconcatrange{#1}{/*}{2}{}\empty
        \right)
    \else
        \MMLcreset
        \xmlall{#1}{/[position()>1]}
    \fi
\stopxmlsetups

% PRESENTATION MATHML
%
% there are some rough edges that need to be sorted out

% helpers

\xmlmapvalue {mml} {normal}                 {\tf}
\xmlmapvalue {mml} {double-struck}          {\bf}
\xmlmapvalue {mml} {italic}                 {\it}
\xmlmapvalue {mml} {fraktur}                {\bf}
\xmlmapvalue {mml} {script}                 {\tf}
\xmlmapvalue {mml} {bold}                   {\bf}
\xmlmapvalue {mml} {bold-italic}            {\bi}
\xmlmapvalue {mml} {bold-fraktur}           {\bf}
\xmlmapvalue {mml} {bold-script}            {\bf}
\xmlmapvalue {mml} {sans-serif}             {\ss}
\xmlmapvalue {mml} {bold-sans-serif}        {\ss\bf}
\xmlmapvalue {mml} {sans-serif-italic}      {\ss\it}
\xmlmapvalue {mml} {sans-serif-bold-italic} {\ss\bi}
\xmlmapvalue {mml} {monospace}              {\tt}

% todo: displaystyle=true/false (or whatever else shows up)

\starttexdefinition setmmlmathstyle #1
    \xmlval {mml} {\xmlatt{#1}{mathvariant}} \empty % was: \mmmr
\stoptexdefinition

\starttexdefinition applymmlmathcolor #1#2
    \edef\mmlmathcolor{\xmlatt{#1}{mathcolor}}
    \ifx \mmlmathcolor \empty
        #2
    \else
        \color[\mmlmathcolor]{#2}
    \fi
\stoptexdefinition

% todo: textbackgrounds

\starttexdefinition applymmlmathbackground #1#2
    \edef\mmlmathbackground{\xmlatt{#1}{mathbackground}}
    \ifx \mmlmathbackground \empty
        #2
    \else
        \backgroundline[\mmlmathbackground]{#2}
    \fi
\stoptexdefinition

\newsignal\mmltextsignal % not used

\starttexdefinition applymmlsometext #1#2
     \applymmlmathbackground {#1} {
         \applymmlmathcolor {#1} {
            \setmmlmathstyle {#1}
            #2
        }
    }
\stoptexdefinition

% probably bugged:

\starttexdefinition doMMLfiller #1
    \pushmacro\doMMLfiller
    \let\doMMLfiller\gobbleoneargument
    \gdef\dodoMMLfiller{% where used
        \disablefiller
        \mathematics{#1}
    }
    \hbox {
        \def\normalorfiller##1##2{
            \gdef\dodoMMLfiller{\enablefiller#1}%
            \let\normalorfiller\gobbletwoarguments
        }
        \mathematics{#1}
    }
    \popmacro\doMMLfiller
\stoptexdefinition

% setups

\startxmlsetups mml:mi % todo: mathvariant mathsize mathcolor mathbackground
    \ctxlua{lxml.mml.mi("#1")}
\stopxmlsetups

\startxmlsetups mml:mn % todo: mathvariant mathsize mathcolor mathbackground
    \begingroup
        \mr \ctxlua{lxml.mml.mn("#1")}% no \hbox, would be ok for . , but spoils rest
    \endgroup
\stopxmlsetups

% <m:mo>-</m:mo><m:mn>2</m:mn> and <m:mn>1</m:mn><m:mo>-</m:mo><m:mn>2</m:mn>
%
% spacing between - and 2 is taken care of by tex itself

\startxmlsetups mml:mo
    \doif {\xmlatt{#1}{maxsize}}  {1}     {\settrue\mmlignoredelimiter}
    \doif {\xmlatt{#1}{stretchy}} {false} {\settrue\mmlignoredelimiter}
    \ctxlua{lxml.mml.mo("#1")}
    \setfalse\mmlignoredelimiter
\stopxmlsetups

\startxmlsetups mml:mfenced % {} around separator is needed for spacing
    \def\MMLleft  {\left }% weird
    \def\MMLright {\right}
    \def\MMLmiddle{\middle}
    \ctxlua{lxml.mml.mfenced("#1")}
\stopxmlsetups

\defineoverlay [mml:enclose:box]                [\useMPgraphic{mml:enclose:box}]
\defineoverlay [mml:enclose:roundedbox]         [\useMPgraphic{mml:enclose:roundedbox}]
\defineoverlay [mml:enclose:circle]             [\useMPgraphic{mml:enclose:circle}]
\defineoverlay [mml:enclose:left]               [\useMPgraphic{mml:enclose:left}]
\defineoverlay [mml:enclose:right]              [\useMPgraphic{mml:enclose:right}]
\defineoverlay [mml:enclose:top]                [\useMPgraphic{mml:enclose:top}]
\defineoverlay [mml:enclose:bottom]             [\useMPgraphic{mml:enclose:bottom}]
\defineoverlay [mml:enclose:updiagonalstrike]   [\useMPgraphic{mml:enclose:updiagonalstrike}]
\defineoverlay [mml:enclose:downdiagonalstrike] [\useMPgraphic{mml:enclose:downdiagonalstrike}]
\defineoverlay [mml:enclose:horizontalstrike]   [\useMPgraphic{mml:enclose:horizontalstrike}]
\defineoverlay [mml:enclose:verticalstrike]     [\useMPgraphic{mml:enclose:verticalstrike}]

\startuseMPgraphic{mml:enclose:box}
    draw OverlayBox withpen pencircle scaled (ExHeight/10) ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:roundedbox}
    draw OverlayBox cornered .5ExHeight withpen pencircle scaled (ExHeight/10) ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:circle}
    draw fullcircle xysized(bbwidth(OverlayBox),bbheight(OverlayBox)) withpen pencircle scaled (ExHeight/10) ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:left}
    draw leftboundary OverlayBox withpen pencircle scaled (ExHeight/10) ;
    setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:right}
    draw rightboundary OverlayBox withpen pencircle scaled (ExHeight/10) ;
    setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:top}
    draw topboundary OverlayBox withpen pencircle scaled (ExHeight/10) ;
    setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:bottom}
    draw bottomboundary OverlayBox withpen pencircle scaled (ExHeight/10) ;
    setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:updiagonalstrike}
    path p ; p := OverlayBox enlarged -.25ExHeight ;
    draw llcorner p -- urcorner p withpen pencircle scaled (ExHeight/10) ;
    setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:downdiagonalstrike}
    path p ; p := OverlayBox enlarged -.25ExHeight ;
    draw ulcorner p -- lrcorner p withpen pencircle scaled (ExHeight/10) ;
    setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:horizontalstrike}
    path p ; p := OverlayBox enlarged -.25ExHeight ;
    draw .5[llcorner p,ulcorner p] -- .5[lrcorner p,urcorner p] withpen pencircle scaled (ExHeight/10) ;
    setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic
\startuseMPgraphic{mml:enclose:verticalstrike}
    path p ; p := OverlayBox enlarged -.25ExHeight ;
    draw .5[llcorner p,lrcorner p] -- .5[ulcorner p,urcorner p] withpen pencircle scaled (ExHeight/10) ;
    setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic

\startxmlsetups mml:menclose
    \edef\mmlmenclosenotation{\ctxlua{lxml.mml.menclosepattern("#1")}}
    \ifx\mmlmenclosenotation\empty
        \xmlflush{#1}
    \else
        \doifelse \mmlmenclosenotation {mml:enclose:longdiv} {
            \overline{\left)\strut\xmlflush{#1}\right.}
        } {
            \doifelse \mmlmenclosenotation {mml:enclose:actuarial} {
                \overline{\left.\strut\xmlflush{#1}\right|}
            } {
                \doifelse \mmlmenclosenotation {mml:enclose:radical} {
                    \sqrt{\xmlflush{#1}}
                } {
                    % todo: no framed when longdiv, actuarial or radical ? spec ?
                    \vcenter {
                        \framed
                            [frame=off,strut=no,background={\mmlmenclosenotation}] % offset is kind of undefined
                            {$
                                \expanded{\doifinsetelse {mml:enclose:longdiv} {\mmlmenclosenotation}} {
                                    \overline{\left)\strut\xmlflush{#1}\right.}
                                } {
                                    \expanded{\doifinsetelse {mml:enclose:actuarial} {\mmlmenclosenotation}} {
                                        \overline{\left.\strut\xmlflush{#1}\right|}
                                    } {
                                        \expanded{\doifinsetelse {mml:enclose:radical} {\mmlmenclosenotation}} {
                                            \sqrt{\xmlflush{#1}}
                                        } {
                                            \xmlflush{#1}
                                        }
                                    }
                                }
                            $}
                    }
                }
            }
        }
    \fi
\stopxmlsetups

\xmlmapvalue {mml:mfrac:linethickness} {thin}   {.2pt}
\xmlmapvalue {mml:mfrac:linethickness} {medium} {.4pt}
\xmlmapvalue {mml:mfrac:linethickness} {thick}  {.8pt}

\startxmlsetups mml:mfrac % dodo: handle linethickness in lua + unit
    \begingroup
    \edef\mmlfraclinethickness{\xmlatt{#1}{linethickness}}
    \ifx\mmlfraclinethickness\empty
        \doifelse{\xmlatt{#1}{bevelled}}{true} {
            \left.\mmlfirst{#1}\middle/\mmlsecond{#1}\right.% \thinspace\middle/\thinspace
        } {
            \frac{\mmlfirst{#1}}{\mmlsecond{#1}}
        }
    \else
        \doifXMLvalelse {mml:mfrac:linethickness} \mmlfraclinethickness {
            \scratchdimen\xmlval{mml:mfrac:linethickness}\mmlfraclinethickness{.4pt}
        } {
            \setdimensionwithunit\scratchdimen\mmlfraclinethickness{pt}
        }
        {
            {\mmlfirst{#1}}
                \above\scratchdimen
            {\mmlsecond{#1}}
        }
    \fi
    \endgroup
\stopxmlsetups

\startxmlsetups mml:ms
    \hbox {
        \tf % else encoding problems
        \edef\mmllquote{\xmlatt{#1}{lquote}}
        \edef\mmlrquote{\xmlatt{#1}{rquote}}
        \ifx\mmllquote\empty\symbol[leftquotation]\else\mmllquote\fi
        \applymmlsometext{#1}{\xmlflush{#1}}
        \ifx\mmlrquote\empty\symbol[rightquotation]\else\mmlrquote\fi
    }
\stopxmlsetups

\startxmlsetups mml:mstyle
    \begingroup
        \setmmlmathstyle{#1}
        \xmlflush{#1}
    \endgroup
\stopxmlsetups

\setupMMLappearance[text][\c!alternative=\v!a] % a=normal, b=keep spaces

\startxmlsetups mml:mtext
    \domathtext {
        \applymmlsometext{#1}{
            \doifelse\MMLscriptsalternative\v!a {
               %\ctxlua{lxml.mml.stripped(\!!bs\xmlflush{#1}\!!es)}
                \ignorespaces
                \xmlflush{#1}
                \unskip
            } {
                \xmlflush{#1}
            }
        }
    }
\stopxmlsetups

\startxmlsetups mml:merror
    \hbox{$\displaystyle\xmlflush{#1}$}
\stopxmlsetups

\startxmlsetups mml:mphantom
%     \phantom{\ignorespaces{}\xmlflush{#1}\unskip} % watch spacing {} hack
    \phantom{\mathstyle{\ignorespaces{}\xmlflush{#1}\unskip}}%
%     \mktriggereffect\v!hidden
%     \ignorespaces{}\xmlflush{#1}\unskip % no attributes in math yet
%     \mktriggereffect\v!normal
\stopxmlsetups

\startxmlsetups mml:mpadded % todo
    \xmlflush{#1}
\stopxmlsetups

% mrow

% \startxmlsetups mml:mrow
%     \begingroup
%         \ifcase\xmlcount{#1}{/mml:mo}\relax
%             \xmlflush{#1}
%         \else % no \let
%             \def\MMLleft  {\left }
%             \def\MMLright {\right}
%             \def\MMLmiddle{\middle}
%             \enabledelimiter
%             \checkdelimiters{\xmlall{#1}{/mml:mo}}
%             \fakeleftdelimiter
%             \xmlflush{#1}
%             \fakerightdelimiter
%             \disabledelimiter
%         \fi
%     \endgroup
% \stopxmlsetups

% option: no fenced

\startxmlsetups mml:mrow
    \begingroup
        \edef\nofmmlrows{\xmlcount{#1}{/mml:mo}}%
        \ifnum\nofmmlrows=\plustwo
            \xmldoifelse {#1} {/mml:mo[position()==1 or position()==\nofmmlrows]} {% we need a {}
                \def\MMLleft  {\left }
                \def\MMLright {\right}
                \def\MMLmiddle{\middle}
                \enabledelimiter
                \checkdelimiters{\xmlall{#1}{/mml:mo}}
                \fakeleftdelimiter
                \xmlflush{#1}
                \fakerightdelimiter
                \disabledelimiter
            } {
                \xmlflush{#1}
            }
        \else
            \xmlflush{#1}
        \fi
    \endgroup
\stopxmlsetups

\startxmlsetups mml:msqrt
    \sqrt{\xmlflush{#1}}
\stopxmlsetups

\startxmlsetups mml:mroot
   \root{\mmlsecond{#1}}\of{\mmlfirst{#1}}
\stopxmlsetups

\setupMMLappearance[scripts][\c!alternative=\v!a] % {} rond base

\startxmlsetups mml:msub
    \doifelse\MMLscriptsalternative\v!a {
        {\mmlfirst{#1}}_{\mmlsecond{#1}}
    } {
         \mmlfirst{#1} _{\mmlsecond{#1}}
    }
\stopxmlsetups

\startxmlsetups mml:msup
    \doifelse\MMLscriptsalternative\v!a {
        {\mmlfirst{#1}}^{\mmlsecond{#1}}
    } {
         \mmlfirst{#1} ^{\mmlsecond{#1}}
    }
\stopxmlsetups

\startxmlsetups mml:msubsup
    \doifelse\MMLscriptsalternative\v!a {
        {\mmlfirst{#1}}_{\mmlsecond{#1}}^{\mmlthird{#1}}
    } {
         \mmlfirst{#1} _{\mmlsecond{#1}}^{\mmlthird{#1}}
    }
\stopxmlsetups

\def\mmlexecuteifdefined#1%
  {\ifx#1\empty
     \expandafter\secondoftwoarguments
   \else\ifcsname#1\endcsname
     \expandafter\expandafter\expandafter\firstoftwoarguments
   \else
     \expandafter\expandafter\expandafter\secondoftwoarguments
   \fi\fi
   {\csname#1\endcsname}}

\startxmlsetups mml:mover
%     \mathop {
        \edef\mmlovertoken{\xmlraw{#1}{/mml:*[2]}}
        \doifelse{\utfmathclass\mmlovertoken}{accent} {
            \edef\mmlovercommand{\utfmathcommand\mmlovertoken}
            \mmlexecuteifdefined\mmlovercommand\mathematics{\mmlfirst{#1}}
        } {
            \edef\mmlbasetoken{\xmlraw{#1}{/mml:*[1]}}
            \edef\mmlbasecommand{\utfmathfiller\mmlbasetoken}
            \edef\mmlovercommand{\utfmathfiller\mmlovertoken}
            \vbox {
                \mathsurround\zeropoint \ialign {
                    \hss##\hss\crcr
                    \noalign{\kern3\onepoint}%
                    \mmlexecuteifdefined\mmlovercommand{\mathematics{\mmlsecond{#1}}}\crcr
                    \noalign{\kern3\onepoint\nointerlineskip}%
                    \mmlexecuteifdefined\mmlbasecommand{\mathematics{\mmlfirst{#1}}}\crcr
                }
            }
        }
%     }
%     \limits % spoils spacing
\stopxmlsetups

\startxmlsetups mml:munder
%     \mathop {
        \edef\mmlundertoken{\xmlraw{#1}{/mml:*[2]}}
        \doifelse{\utfmathclass\mmlundertoken}{accent} {
            \edef\mmlundercommand{\utfmathcommand\mmlundertoken}
            \mmlexecuteifdefined\mmlundercommand\mathematics{\mmlfirst{#1}}
        } {
            \edef\mmlbasetoken   {\xmlraw{#1}{/mml:*[1]}}
            \edef\mmlbasecommand {\utfmathfiller\mmlbasetoken}
            \edef\mmlundercommand{\utfmathfiller\mmlundertoken}
            \vtop {
                \mathsurround\zeropoint \ialign {
                    \hss##\hss\crcr
                    \mmlexecuteifdefined\mmlbasecommand {\mathematics{\mmlfirst{#1}}}\crcr
                    \noalign{\kern3\onepoint\nointerlineskip}%
                    \mmlexecuteifdefined\mmlundercommand{\mathematics{\mmlsecond{#1}}}\crcr
                    \noalign{\kern3\onepoint}
                }
            }
        }
%     }
%     \limits % spoils spacing
\stopxmlsetups

\startxmlsetups mml:munderover
    \edef\mmlbasetoken{\xmlraw{#1}{/mml:*[1]}}
    \edef\mmlbasecommand{\utfmathcommand\mmlbasetoken}
    \mmlexecuteifdefined\mmlbasecommand{\mathematics{\mmlfirst{#1}}}_{\mmlsecond{#1}}^{\mmlthird{#1}}
\stopxmlsetups

% tables (mml:mtable, mml:mtr, mml:mlabledtr, mml:mtd)

\startxmlsetups mml:mtable % some more attributes need to be supported
    \vcenter{\ctxlua{lxml.mml.mtable("#1")}}
\stopxmlsetups

\startxmlsetups mml:mcolumn
    \ctxlua{lxml.mml.mcolumn("#1")}
\stopxmlsetups

\def\mmlsetfakewidth#1{\setbox\scratchbox\hbox{#1}\scratchdimen\wd\scratchbox}

\def\mmlmcolumndigitspace     {\mmlsetfakewidth     {0}\kern\scratchdimen}
\def\mmlmcolumndigitrule      {\mmlsetfakewidth     {0}\vrule width \scratchdimen height .2pt depth .2pt\relax}
\def\mmlmcolumnsymbolrule     {\mmlsetfakewidth{\times}\vrule width \scratchdimen height .2pt depth .2pt\relax}
\def\mmlmcolumnpunctuationrule{\mmlsetfakewidth     {.}\vrule width \scratchdimen height .2pt depth .2pt\relax}

\startxmlsetups mml:mspace
    \begingroup
    \edef\mmlspacetext{\xmlatt{#1}{spacing}}
    \ifx\mmlspacetext\empty
        \!!widtha \xmlattdef{#1}{width} \!!zeropoint % must be string
        \!!heighta\xmlattdef{#1}{height}\!!zeropoint
        \!!deptha \xmlattdef{#1}{depth} \!!zeropoint
        \ifdim\!!heighta=\zeropoint
            \ifdim\!!deptha=\zeropoint\else
                \hbox{\vrule\!!depth\!!deptha\!!height\zeropoint\!!width\zeropoint}%
            \fi
        \else
            \hbox{\vrule\!!depth\zeropoint\!!height\!!heighta\!!width\zeropoint}%
        \fi
        \ifdim\!!widtha=\zeropoint\else
            \hskip\!!widtha
        \fi
    \else
        \phantom{\mathstyle{\mmlspacetext}}%
    \fi
    \endgroup
\stopxmlsetups

% later we can do a better job by manipulating node lists

\startxmlsetups mml:mline
    % new, rather undefined, we need to capture a few keywords
    \edef\mmllinewidth {\xmlatt{#1}{linethickness}}
    \edef\mmllinetext  {\xmlatt{#1}{spacing}}
    \edef\mmllinelength{\xmlattdef{#1}{length}\!!zeropoint}
    \ifx\mmllinewidth\empty
        \!!deptha.5\linewidth
    \else
        \!!deptha.5\dimexpr\mmllinewidth\relax
    \fi
    \!!heighta\!!deptha
    \ifx\mmllinetext\empty
        \ifx\mmllinelength\empty
            \!!widtha\zeropoint
        \else
            \!!widtha\mmllinelength
        \fi
    \else
        \setbox\scratchbox\hbox{\mathematics{\mathstyle{\mmllinetext}}}% not ok
        \!!widtha\wd\scratchbox
    \fi
    \hbox{\vrule\!!width\!!widtha\!!depth\!!deptha\!!height\!!heighta}
\stopxmlsetups

\startxmlsetups mml:mglyph % probably never ok
    \begingroup
    \edef\mmlglyphfontfamily{\xmlatt   {#1}{fontfamily}}
    \edef\mmlglyphalt       {\xmlattdef{#1}{alt}{unknown}}
    \edef\mmlglyphindex     {\xmlatt   {#1}{index}}
    \ifx \mmlglyphfontfamily \empty
        \hbox{\tttf[no fontfamily specified for \mmlglyphalt]}
    \else\ifx\mmlglyphindex\empty
        \hbox{\tttf[no index specified for \mmlglyphalt]}
    \else
        \getglyph\mmlglyphfontfamily\mmlglyphindex
    \fi\fi
    \endgroup
\stopxmlsetups

\startxmlsetups mml:maligngroup \stopxmlsetups % will be done when needed
\startxmlsetups mml:malignmark  \stopxmlsetups % will be done when needed

\startxmlsetups mml:none        \stopxmlsetups
\startxmlsetups mml:mprescripts \stopxmlsetups

\startxmlsetups mml:mmultiscripts
    \ctxlua{lxml.mml.mmultiscripts("#1")}
\stopxmlsetups

\stopmodule

\protect \endinput

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% TODO:

\startmoduletestsection

\def\xflushXMLstackwith#1#2#3#4% num bgroup egroup whatever
  {\dostepwiserecurse{#1}\XMLstacklevel\plusone
     {#2\relax
      \ifnum\recurselevel>#1\relax#4\fi
      \getXMLstackdata\recurselevel
      #3}}

\def\xflushXMLstackfrom#1#2#3%
  {\dostepwiserecurse{#1}\XMLstacklevel\plusone
     {#2\getXMLstackdata\recurselevel#3}}

% <apply><divide/>
%     <apply><minus/>
%         <apply><minus/><ci>b</ci></apply>
%         <apply><minus/><ci>b</ci></apply>
%         <apply><root/> <ci>a</ci></apply>
%     </apply>
%     <apply><minus/>
%         <apply><minus/><ci>b</ci><ci>b</ci></apply>
%         <apply><minus/><ci>b</ci></apply>
%         <apply><root/> <ci>a</ci></apply>
%     </apply>
% </apply>

\startxmlsetups mml:minus
    \doif \MMLsignreduction \v!yes {
        \setMMLcreset{fn,\MMLcfunctionlist}
    }
    \ifcase\XMLstacklevel
    \or
       % self
    \or
       -\getXMLstackdata\plustwo
    \else
        \dostepwiserecurse \plustwo \XMLstacklevel \plusone {
            \begingroup
            \doifelse {\getXMLstackname\recurselevel} {apply} {
                \ifnum\recurselevel=\plustwo
                    \begingroup
                    \dodoifelseMMCfunctioninapply \recurselevel {minus} {
                        \ifnum\XMLstacklevel>\plustwo
                            \endgroup
                        \else
                            \endgroup
                            \MMLcreset
                        \fi
                    } {
                        \endgroup
                    }
                \else
                    \doifelseMMCfunctioninapply \recurselevel {\MMLcfunctionlist,\MMLcconstructlist} {
                        \MMLcreset
                    } {
                    }
                \fi
            } {
            }
            \getXMLstackdata\recurselevel
            \ifnum\recurselevel<\XMLstacklevel\relax
                -
            \fi
            \endgroup
        }
    \fi
\stopxmlsetups

\stopmoduletestsection