%% xyarrow.tex from $Id: xyarrow.doc,v 2.12 1994/10/25 11:34:25 kris Exp $
%%
%% XY-pic ``Arrows and Paths'' feature.
%% Copyright (c) 1991-1994 Kristoffer H. Rose <kris@diku.dk>
%%
%% This file is part of the XY-pic package for graphs and diagrams in TeX.
%% See the companion README and INSTALL files for further information.
%% Copyright (c) 1991-1994 Kristoffer H. Rose <kris@diku.dk>
%%
%% The XY-pic package is free software; you can redistribute it and/or modify
%% it under the terms of the GNU General Public License as published by the
%% Free Software Foundation; either version 2 of the License, or (at your
%% option) any later version.
%%
%% The XY-pic package is distributed in the hope that it will be useful, but
%% WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
%% or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
%% for more details.
%%
%% You should have received a copy of the GNU General Public License along
%% with this package; if not, write to the Free Software Foundation, Inc.,
%% 675 Mass Ave, Cambridge, MA 02139, USA.
%%
\ifx\xyloaded\undefined \input xy \fi
\xyprovide{arrow}{Arrow and Path feature}{\stripRCS$Revision: 2.12 $}%
 {Kristoffer H.~Rose}{kris@diku.dk}%
 {Computer Science, University of Copenhagen, Universitetsparken~1,
 DK--2100 K{\o}benhavn~{\O}}
\message{path,}
\xydef@\PATH{\afterPATH{}}
\xylet@\afterPATH@=\empty
\xydef@\afterPATH#1{\xy@@\save@
 \DN@##1{\def\afterPATH@{\restore \def\afterPATH@{##1}#1}}%
 \expandafter\next@\expandafter{\afterPATH@}%
 \let\PATHfail@@=\empty
 \let\PATHnext@@=\empty
 \let\PATHevery@@=\empty
 \let\PATHlast@@=\empty
 \let\PATHeverysub@@=\empty
 \let\PATHbeforelabels@@=\empty
 \let\PATHafter@@=\empty
 \xy@{\afterPATH{#1}}{\def\PATHslide@@{\z@}}%
 \def\PATHcontinue@@{\xyFN@\PATH@}%
 \xyFN@\PATH@}
\xynew@{if}\ifPATHsingle@
\xydef@\PATH@{%
 \ifx \space@\next \expandafter\DN@\space{\xyFN@\PATH@}%
 \else\ifPATHsingle@ \let\next@=\PATH@single
 \else \let\next@=\PATH@normal \fi\fi \next@}
\xydef@\PATH@normal{%
 \ifx ~\next \DN@ ~{\xyFN@\PATHsetting@}%
 \else \addRQ@\ifx \next \addRQ@\DN@{\xy@'{}\xyFN@\PATHstraight@}%
 \else \addLQ@\ifx \next \addLQ@\DN@{\xy@`{}\xyFN@\PATHturn@}%
 \else\ifx \PATHfail@@\PATH@x \DN@{\xyFN@\PATHlast@}%
 \else
 \DNii@{\let\PATHfail@@=\PATH@x \xyFN@\PATH@}%
 \DN@{\expandafter\nextii@\PATHfail@@}%
 \fi\fi\fi\fi \next@}
\xylet@\PATHnext@@=\empty
\xylet@\PATHevery@@=\empty
\xylet@\PATHlast@@=\empty
\xylet@\PATHeverysub@@=\empty
\xylet@\PATHbeforelabels@@=\empty
\xylet@\PATHafter@@=\empty
\xylet@\PATHfail@@=\empty
\xydef@\PATHsetting@{%
 \ifx \space@\next \expandafter\DN@\space{\xyFN@\PATHsetting@}%
 \else\ifx \bgroup\next
 \DN@##1{\xy@{~{##1}}{}\def\PATHfail@@{##1}\xyFN@\PATH@}%
 \else \addEQ@\ifx \next
 \addEQ@\DN@##1{\xy@{~={##1}}{}\def\PATHevery@@{##1}\xyFN@\PATH@}%
 \else \addLT@\ifx \next
 \addLT@\DN@##1{\xy@{~<{##1}}{}\def\PATHnext@@{##1}\xyFN@\PATH@}%
 \else \addGT@\ifx \next
 \addGT@\DN@##1{\xy@{~>{##1}}{}\def\PATHlast@@{##1}\xyFN@\PATH@}%
 \else \addDASH@\ifx \next
 \addDASH@\DN@##1{\xy@{~-{##1}}{}\def\PATHeverysub@@{##1}\xyFN@\PATH@}%
 \else \addPLUS@\ifx \next
 \addPLUS@\DN@##1{\xy@{~+{##1}}{}\def\PATHbeforelabels@@{##1}\xyFN@\PATH@}%
 \else \ifx /\next
 \DN@/##1{\xy@{~/{##1}}{}\def\PATHafter@@{##1}\xyFN@\PATH@}%
 \else
 \xyerror@{Unknown \string~ setting: \meaning\next}%
 {See the XY-pic arrow feature documentation for help.}%
 \fi\fi\fi\fi\fi\fi\fi\fi \next@}
\xylet@\PATHinit@@=\empty
\xylet@\PATHextra@@=\empty
\xylet@\PATHpost@@=\empty
\xylet@\PATHcontinue@@=\empty
\xydef@\PATHstraight@{%
 \def\PATHinit@@{\PATHinitstraight@}\def\PATHextra@@{}\def\PATHpost@@{}%
 \xy@@\pfromc@ \PATHafterPOS{\xyFN@\PATHsegment@}}
\xydef@\PATHlast@{%
 \def\PATHinit@@{\PATHinitstraight@}%
 \def\PATHextra@@{\let\PATHcontinue@@=\afterPATH@
 \addGT@\PATHaction@\PATHlast@@ \let\PATHlast@@=\empty}%
 \def\PATHpost@@{}%
 \xy@@\pfromc@ \PATHafterPOS{\xyFN@\PATHsegment@}}
\xydef@\PATHinitstraight@{\xy@@{\setupDirection@ \dimen@=\PATHslide@@
 \dimen@ii=-\sinDirection\dimen@
 \ifPATHomitslide@@\else\advance\Xp\dimen@ii\fi \advance\Xc\dimen@ii
 \dimen@ii= \cosDirection\dimen@
 \ifPATHomitslide@@\else\advance\Yp\dimen@ii\fi \advance\Yc\dimen@ii
 \PATHomitslide@@false \resetupDirection@}}
\xydef@\PATHslide@@{\z@}
\xynew@{if}\ifPATHomitslide@@
\xydef@\PATHsegment@{%
 \addLT@\ifx\next
 \addGT@{\addLT@\DN@##1}{%
 \xy@{<##1>}{\dimen@=##1\relax \edef\PATHslide@@{\the\dimen@}}%
 \xyFN@\PATHsegment@@}%
 \else \let\next@=\PATHsegment@@
 \fi \next@}
\xylet@\cfrominitial@@=\relax
\xylet@\cfromfinal@@=\relax
\xydef@\PATHsegment@@{\PATHinit@@ \resetbreaks
 \addEQ@\PATHaction@\PATHevery@@
 \addLT@\PATHaction@\PATHnext@@ \let\PATHnext@@=\empty
 \PATHextra@@
 \xy@@{\edef\cfrominitial@@{\cfromthep@}\edef\cfromfinal@@{\cfromthec@}%
 \edef\pfromlastbreak@@{\pfromthep@}}\resetbreaks%
 \def\subsegmentno@{0}\toks@={}%
 \DN@{\xyFN@\PATHlabels@}\expandafter\next@\PATHbeforelabels@@}
\xylet@\PATHlabelit@@=\empty
\xydef@\PATHlabels@{%
 \ifx \space@\next \expandafter\DN@\space{\xyFN@\PATHlabels@}%
 \else \ifx ^\next 
 \DN@##1{\xy@^{}\let\PATHlabelit@@=\PATHlabelabove@ \DNii@{}\xyFN@\PATHanchor@}%
 \else \ifx _\next
 \DN@##1{\xy@_{}\let\PATHlabelit@@=\PATHlabelbelow@ \DNii@{}\xyFN@\PATHanchor@}%
 \else \ifx |\next
 \DN@|{\xy@|{}\let\PATHlabelit@@=\PATHlabelbreak@ \DNii@{}\xyFN@\PATHanchor@}%
 \else
 \let\next@=\PATHsubsegments@
 \fi\fi\fi\fi \next@}
\xydef@\PATHanchor@{\begingroup \toks@={}\PATHanchor@i}
\xydef@\PATHanchor@i{%
 \ifx \space@\next \expandafter\DN@\space{\xyFN@\PATHanchor@i}%
 \else\addDASH@\ifx \next
 \addDASH@\DN@{\expandafter\addtotoks@\expandafter{\PATHanchor@toks}%
 \xyFN@\PATHanchor@i}%
 \else
 \DNii@##1{\endgroup\afterPLACE{\xyFN@\PATHit@}##1}%
 \DN@{\expandafter\nextii@\expandafter{\the\toks@}}%
 \fi\fi \next@}
{\xyuncatcodes \gdef\next{<>(.5)}}
\xylet@\PATHanchor@toks=\next
\xydef@\PATHit@{%
 \ifx \space@\next \expandafter\DN@\space{\xyFN@\PATHit@}%
 \else \ifx *\next \DN@*##1##{\PATHlabelit@@{##1}}%
 \else \addAT@\ifx\next \addAT@\DN@##1##{\PATHlabelit@@{\dir##1}}%
 \else \DN@{\PATHlabelit@@{}}%
 \fi\fi\fi \next@}
\xydef@\PATHsubsegments@{\the\toks@
 \toks@={}\xy@@{\ifx\bstartPLACE@\relax\else\def\bendPLACE@{1}\fi
 \pfromlastbreak@@\cfromfinal@@\setupDirection@}%
 \addDASH@\PATHaction@\PATHeverysub@@
 \PATHpost@@ \PATHaction@/\PATHafter@@ \PATHcontinue@@}
\xydef@\PATHaction@default#1#2{\xy@{PATHaction#1{#2}}{}\POS#2\relax}
\xylet@\PATHaction=\PATHaction@default
\xydef@\PATHaction@#1#2{\expandafter\PATHaction\expandafter#1\expandafter{#2}}
\xylet@\PATHafterPOS@default=\afterPOS
\xylet@\PATHafterPOS=\PATHafterPOS@default
\xydef@\PATHlastout@@{3}
\xydef@\PATHturn@{\afterCIRorDIAG\PATHturn@cir\PATHturn@diag}
\xydef@\PATHturn@cir{\toks@={\xy@@{%
 \count@=\CIRin@@ \ifnum\count@<4\else\advance\count@-4\fi
 \count@@=\CIRout@@ \ifnum\count@@<4\else\advance\count@@-4\fi
 \ifnum\count@=\count@@ \xyerror@{<turn> cannot be half or full}{%
You asked for a <turn>ed segment with parallel in- and out-direction.^^J%
This is not allowed because it is not possible to position it uniquely.}\fi}}%
 \edef\next@{{\CIRin@@}{\expandafter\noexpand\CIRorient@@}{\CIRout@@}}%
 \expandafter\PATHturn@i\next@}
\xydef@\PATHturn@diag{\toks@={\xy@@{%
 \setupDirection@ \count@=\CIRin@@ \dimen@=\xydashl@ \ABfromdiag@
 \ifdim \sinDirection\A@>\cosDirection\B@ \def\CIRorient@@{\CIRacw@}%
 \advance\count@\ifnum\count@<6 \tw@ \else -6\fi
 \else \def\CIRorient@@{\CIRcw@}%
 \advance\count@\ifnum\count@>\@ne -\tw@ \else 6\fi
 \fi
 \edef\CIRout@@{\the\count@}}}%
 \edef\next@{{\CIRin@@}{}{}}%
 \expandafter\PATHturn@i\next@}
\xylet@\PATHpostpos@@=\empty
\xydef@\PATHturn@i#1#2#3{%
 \DN@##1{\def\PATHinit@@{\xy@@{%
 \def\CIRin@@{#1}\def\CIRorient@@{#2}\def\CIRout@@{#3}%
 \ifnum\CIRin@@=8 \let\CIRin@@=\PATHlastout@@ \fi
 \R@=\turnradius@
 ##1\relax
 \count@=\CIRin@@
 \ifPATHomitslide@@ \dimen@=-\PATHslide@@
 \ABfromdiag@ \advance\Xp-\B@ \advance\Yp\A@ \fi
 \enter@{\pfromthep@ \basefromthebase@}%
 \dimen@=\expandafter\ifx\CIRorient@@\CIRcw@-\fi\R@
 \ABfromdiag@ \advance\Xp-\B@ \advance\Yp\A@
 \Xorigin=\Xp \Yorigin=\Yp
 \dimen@=\xydashl@ \ABfromdiag@ \Rc=\A@ \Uc=\B@
 \count@=\CIRout@@
 \dimen@=\expandafter\ifx\CIRorient@@\CIRcw@-\fi\R@
 \ABfromdiag@ \advance\Xc-\B@ \advance\Yc\A@
 \dimen@=\xydashl@ \Xp=\Xc \Yp=\Yc
 \ABfromdiag@ \advance\Xp-\A@ \advance\Yp-\B@
 \intersect@
 \count@=\CIRin@@ \dimen@=\p@ \ABfromdiag@
 \edef\next@{\expandafter\removePT@\the\A@}%
 \edef\nextii@{\expandafter\removePT@\the\B@}%
 \A@=\Xc \advance\A@-\Xorigin \B@=\Yc \advance\B@-\Yorigin
 \ifdim \next@\A@<-\nextii@\B@
 \dontleave@ \cfromp@
 \count@=\CIRin@@ \advance\count@\ifnum\count@<4 +4\else -4\fi
 \dimen@=\xydashl@ \Directionfromdiag@
 \the\Edgec\z@
 \count@=\CIRin@@ \dimen@=\expandafter\ifx\CIRorient@@\CIRcw@-\fi\R@
 \ABfromdiag@ \advance\Xc-\B@ \advance\Yc\A@
 \dimen@=5sp \ABfromdiag@ \advance\Xc\A@ \advance\Yc\B@
 \fi
 \dimen@ii=\expandafter\ifx\CIRorient@@\CIRacw@-\fi\PATHslide@@
 \advance\R@\dimen@ii
 \drop@\literal@{\hbox\bgroup\cir@i}%
 \Xp=\Xc \Yp=\Yc
 \count@=\CIRout@@
 \dimen@=\expandafter\ifx\CIRorient@@\CIRacw@-\fi\Rc
 \ABfromdiag@ \advance\Xp-\B@ \advance\Yp\A@
 \edef\PATHpostpos@@{\Xc=\the\Xp \Yc=\the\Yp \noexpand\czeroEdge@
 \noexpand\PATHomitslide@@true}%
 \count@=\CIRin@@
 \dimen@=\expandafter\ifx\CIRorient@@\CIRacw@-\fi\Rc
 \ABfromdiag@ \advance\Xc-\B@ \advance\Yc\A@ \czeroEdge@
 \leave@
 \count@=\CIRin@@ \dimen@=\PATHslide@@
 \ABfromdiag@ \advance\Xp-\B@ \advance\Yp\A@
 \edef\PATHlastout@@{\CIRout@@}%
 \count@=\CIRout@@ \dimen@=\xydashl@ \Directionfromdiag@}}}%
 \expandafter\next@\expandafter{\the\toks@}\toks@={}%
 \def\PATHextra@@{}%
 \def\PATHpost@@{\xy@@\PATHpostpos@@}%
 \xyFN@\PATHturn@ii}
\xydef@\PATHturn@ii{%
 \ifx /\next
 \DN@ /{\afterassignment\nextii@\dimen@=}%
 \DNii@{%
 \edef\next@{\noexpand\xy@@{\edef\noexpand\turnradius@{\the\dimen@}}}\next@
 \xy@@\pfromc@ \PATHafterPOS{\xyFN@\PATHsegment@}}%
 \else \DN@{\xy@@\pfromc@ \PATHafterPOS{\xyFN@\PATHsegment@}}\fi
 \next@}
\xydef@\ABfromdiag@{\ifcase\count@\relax
 \A@=-.7071\dimen@ \B@=-.7071\dimen@ \or \A@=\z@ \B@=-\dimen@
 \or \A@=+.7071\dimen@ \B@=-.7071\dimen@ \or \A@=\dimen@ \B@=\z@
 \or \A@=+.7071\dimen@ \B@=+.7071\dimen@ \or \A@=\z@ \B@=+\dimen@
 \or \A@=-.7071\dimen@ \B@=+.7071\dimen@ \or \A@=-\dimen@ \B@=\z@
 \else\xybug@{impossible <diag>?}\fi}
\xydef@\turnradius@{10pt}
\xydef@\turnradius{\afterADDOP{\Addop@@\turnradius@}}
\xydef@\PATHlabelabove@#1#2{\xy@@\save@ \droplabel@\belowDirection@{#1}{#2}%
 \xyFN@\PATHlabelalias@}
\xydef@\PATHlabelbelow@#1#2{\xy@@\save@ \droplabel@\aboveDirection@{#1}{#2}%
 \xyFN@\PATHlabelalias@}
\xydef@\droplabel@#1#2#3{%
 \xy@@{\enter@\DirectionfromtheDirection@}%
 \DN@{#2}\ifx\next@\empty \xy@@ix@{\labelbox{#3}}%
 \else \xy@@ix@{#2{#3}}\fi
 \xy@@{%
 \setbox\z@=\expandafter\object\the\toks9
 \advance\Lc\labelmargin@ \advance\Rc\labelmargin@
 \advance\Dc\labelmargin@ \advance\Uc\labelmargin@
 \A@=\Xc \B@=\Yc #1\xydashl@ \the\Edgec\thr@@
 \advance\A@-\Xc \advance\B@-\Yc \advance\Xc 2\A@ \advance\Yc 2\B@
 \ht\z@=\Uc \dp\z@=\Dc 
 \setbox\lastobjectbox@=\hbox{\kern\labelmargin@\Drop@@\kern\labelmargin@}%
 \drop@{\box\lastobjectbox@}{}%
 \leave@}}%
\xylet@\labelmargin@=\objectmargin@
\xydef@\labelmargin{\afterADDOP{\Addop@@\labelmargin@}}
\xylet@\pfromlastbreak@@=\empty
\xylet@\breakcount@=\relax
\def\next{\cfrominitial@@}
\expandafter\let\csname cfrombreak0@\endcsname=\next
\xydef@\resetbreaks{%
 \xy@@{\let\bstartPLACE@=\relax \let\bendPLACE@=\relax}}
\xydef@\invisbreaks{\xy@@{\def\bstartPLACE@{}}}
\xydef@\initbreaks{\xy@@{\ifx\bstartPLACE@\relax
 \def\bstartPLACE@{0}\def\bendPLACE@{1}\fi}}
\xydef@\lastbreaks{\xy@@{\ifx\bstartPLACE@\relax
 \def\bstartPLACE@{0}\fi\def\bendPLACE@{1}}}
\xylet@\bstartPLACE@=\relax
\xylet@\bendPLACE@=\relax
\xydef@\PATHlabelbreak@#1#2{%
 \DN@{#1}\ifx\next@\empty \drop\labelbox{#2}%
 \else \drop#1{#2}\fi \xy@@{\save@}%
 \count@=\subsegmentno@ \advance\count@\@ne
 \edef\subsegmentno@{\the\count@}%
 \DN@##1##2##3##4{%
 \addtotoks@{%
 \xy@@{\ifx\bstartPLACE@\relax\def\bstartPLACE@{0}%
 \else\edef\bstartPLACE@{\bendPLACE@}\fi \def\bendPLACE@{##4}}}%
 \xy@@{\expandafter\edef\csname cmergebreak##1@\endcsname
 {\DirectionfromtheDirection@ \cmergethecz@}%
 \expandafter\def\csname cfrombreak##3@\endcsname{\cfromfinal@@}%
 \expandafter\edef\csname cfrombreak##1@\endcsname
 {\DirectionfromtheDirection@ \cfromthec@}}%
 \addtotoks@{%
 \xy@@{\pfromlastbreak@@ 
 \csname cfrombreak##3@\endcsname
 \csname cmergebreak##1@\endcsname }%
 \addDASH@\PATHaction@\PATHeverysub@@
 \xy@@{\csname cfrombreak##2@\endcsname
 \csname cmergebreak##1@\endcsname 
 \edef\pfromlastbreak@@{\pfromthec@}\def\bstartPLACE@{##4}}}}%
 \count@@=\count@ \advance\count@\@ne \advance\count@@\m@ne
 \ifx\PLACEf@\empty 
 \edef\tmp@{{\subsegmentno@}{\the\count@@}{\the\count@}{}}%
 \else
 \edef\tmp@{{\subsegmentno@}{\the\count@@}{\the\count@}\PLACEf@}%
 \fi \expandafter\next@\tmp@
 \xyFN@\PATHlabelalias@}
\xydef@\cmergethecz@{%
 \noexpand\cmergez@{\the\Yc}{\the\Xc}{\the\Dc}{\the\Uc}{\the\Lc}{\the\Rc}}
\xydef@\cmergez@#1#2#3#4#5#6{\the\Edgec4%
 \A@=#2\relax \B@=#1\relax
 \Lc=-\A@ \advance\Lc+#5\advance\Lc+\Xc \ifdim\Lc<\z@ \Lc=\z@ \fi
 \Rc=+\A@ \advance\Rc+#6\advance\Rc-\Xc \ifdim\Rc<\z@ \Rc=\z@ \fi
 \Dc=-\B@ \advance\Dc+#3\advance\Dc+\Yc \ifdim\Dc<\z@ \Dc=\z@ \fi
 \Uc=+\B@ \advance\Uc+#4\advance\Uc-\Yc \ifdim\Uc<\z@ \Uc=\z@ \fi
 \DN@{\Edgec={\rectangleEdge}}%
 \ifdim\Lc=\z@ \ifdim\Uc=\z@ \ifdim\Rc=\z@ \ifdim\Dc=\z@ 
 \DN@{}\fi\fi\fi\fi
 \next@ }
\xydef@\infinitize@#1{\the\Edgec4%
 \dimen@=\Xc \advance\dimen@-\Xp
 \def\next{TT}%
 \DN@{\zeroEdge}\expandafter\DNii@\expandafter{\the\Edgec}%
 \ifx\next@\nextii@ \def\next{TF}\fi
 \if\next
 \ifdim\dimen@<\z@ \Lc=\Xc \advance\Lc-\Xmin \advance\Lc1pc
 \else \ifdim\dimen@>\z@ \Rc=\Xmax \advance\Rc-\Xc \advance\Rc1pc \fi\fi
 \dimen@=\Yc \advance\dimen@-\Yp
 \ifdim\dimen@<\z@ \Dc=\Yc \advance\Dc-\Ymin \advance\Dc1pc
 \else\ifdim\dimen@>\z@ \Uc=\Ymax \advance\Uc-\Yc \advance\Uc1pc \fi\fi
 \Edgec={\rectangleEdge}\fi \let\next=\relax}
\xylet@\labelstyle=\scriptstyle
\xydef@\labelbox#1{\hbox{$\m@th\labelstyle{#1}$}}
\xydef@\PATHlabelalias@{%
 \ifx \space@\next \expandafter\DN@\space{\xyFN@\PATHlabelalias@}%
 \else \addEQ@\ifx \next
 \addEQ@\DN@"##1"{\savealias@{##1}\xyFN@\PATHlabelalias@}%
 \else \DN@{\xy@@\leave@ \PATHlabels@}\fi\fi \next@}
{\xyuncatcodes \gdef\next#1{\POS!C="#1"\relax}}
\xylet@\savealias@=\next
\message{\string\ar,}
\xylet@\arvariant@@=\empty
\xylet@\artail@@=\empty
\xylet@\arstem@@=\empty
\xylet@\arhead@@=\empty
\xylet@\armodifiers@@=\empty
\xylet@\arlabels@@=\empty
\xylet@\arinit@@=\empty
\xylet@\arexit@@=\empty
\xylet@\arcomponent@@=\relax
\xylet@\arcomponenttype@@=\relax
\xylet@\afterarr@@=\relax
\xydef@\ar{%
 \let\arvariant@@=\empty
 \def\artail@@{ {}}%
 \edef\arstem@@{\arvariant@@{-}}%
 \edef\arhead@@{\arvariant@@{>}}%
 \def\armodifiers@@{}%
 \def\arlabels@@{}%
 \def\arinit@@{}%
 \def\arexit@@{}%
 \xyFN@\arr@}
\xydef@\arr@{%
 \ifx \space@\next \expandafter\DN@\space{\xyFN@\arr@}%
 \else \addAT@\ifx\next \addAT@\DN@{\xyFN@\arr@form}%
 \else\ifx |\next
 \DN@ |{\arr@anchor|}%
 \else\ifx ^\next
 \DN@ ^{\arr@anchor^}%
 \else\ifx _\next
 \DN@ _{\arr@anchor_}%
 \else \let\next@=\arr@x \fi\fi\fi\fi\fi \next@}
\xydef@\arr@anchor#1{\begingroup
 \def\PATHlabelit@@##1##2{%
 \DN@####1{\endgroup\expandafter\def\expandafter\arlabels@@
 \expandafter{\arlabels@@ ####1}}%
 \expandafter\next@\expandafter{\the\toks@*##1{##2}}\xyFN@\arr@}%
 \toks@={#1}%
 \def\xy@##1##2{\addtotoks@{##1}}\let\oxy@=\xy@ \let\xy@@ix@=\eat@
 \DNii@{}\xyFN@\PATHanchor@}
\xydef@\arr@form{%
 \ifx \space@\next \expandafter\DN@\space{\xyFN@\arr@form}%
 \else\ifx ^\next \DN@ ^{\xyFN@\arr@i}\edef\arvariant@@{\string^}%
 \else\ifx _\next \DN@ _{\xyFN@\arr@i}\edef\arvariant@@{\string_}%
 \else\ifx 0\next \DN@ 0{\xyFN@\arr@i}\def\arvariant@@{0}%
 \else\ifx 1\next \DN@ 1{\xyFN@\arr@i}\def\arvariant@@{1}%
 \else\ifx 2\next \DN@ 2{\xyFN@\arr@i}\def\arvariant@@{2}%
 \else\ifx 3\next \DN@ 3{\xyFN@\arr@i}\def\arvariant@@{3}%
 \else\ifx \bgroup\next \let\next@=\arr@i
 \else\ifx *\next \DN@ *{\arr@modifiers}%
 \else\ifx /\next \let\next@=\arr@curveslash
 \else\ifx '\next \DN@ '{\arr@curve}%
 \else \let\next@=\arr@error
 \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi \next@}
\xydef@\arr@error#1{\xyerror@{Illegal <form>ation (\meaning\next)}{}%
 \xyFN@\arr@}
\xydef@\arr@i{%
 \ifx \bgroup\next
 \let\arcomponent@@=\arr@ii \let\arcomponenttype@@=\artip@
 \DN@##1{\xyFN@\arcomponent@##1$}%
 \else \DN@{\xyFN@\arr@}%
 \fi \next@}
\xydef@\arr@ii{%
 \ifx $\next \edef\arstem@@{\arvariant@@{-}}\let\next@=\arr@iv
 \else \expandafter\def\expandafter\artail@@\expandafter{\the\toks@}%
 \let\arcomponent@@=\arr@iii \let\arcomponenttype@@=\arconn@
 \DN@{\xyFN@\arcomponent@}\fi \next@}
\xydef@\arr@iii{%
 \expandafter\def\expandafter\arstem@@\expandafter{\the\toks@}%
 \let\arcomponent@@=\arr@iv \let\arcomponenttype@@=\artip@
 \xyFN@\arcomponent@}
\xydef@\arr@iv{%
 \expandafter\def\expandafter\arhead@@\expandafter{\the\toks@}%
 \ifx $\next \DN@ ${\xyFN@\arr@}%
 \else \xyerror@{illegal <arrow>: \meaning\next\space not valid}{}\fi \next@}
\xydef@\arr@x{%
 \let\PATHlabelbreak@@=\arlabelbreak@
 \toks@={\arr@PATH}%
 \expandafter\addtotoks@\expandafter{\expandafter{\artail@@}}%
 \expandafter\addtotoks@\expandafter{\expandafter{\arstem@@}}%
 \expandafter\addtotoks@\expandafter{\expandafter{\arhead@@}}%
 \expandafter\addtotoks@\expandafter{\expandafter{\armodifiers@@}}%
 \expandafter\addtotoks@\expandafter{\expandafter{\arinit@@}}%
 \expandafter\addtotoks@\expandafter{\expandafter{\arexit@@}}%
 \expandafter\addtotoks@\expandafter{\expandafter{\arlabels@@}}%
 \addtotoks@{\afterarr@@}%
 \expandafter\DNii@\expandafter{\the\toks@}\toks@={}%
 \nextii@}
{\xyuncatcodes \gdef\next#1#2#3#4#5#6#7#8{\afterPATH{#8}%
 ~={#5\invisbreaks\connect i#4\dir#2\resetbreaks}%
 ~<{\arsegment{?<*#4\dir#1}0}%
 ~>{\arsegment{?>*#4\dir#3}1}%
 ~-{\initbreaks\connect #4\dir#2}%
 ~/{#6}%
 ~+{#7}}}
\xylet@\arr@PATH=\next
\xylet@\artmp@@=\relax
\xydef@\arsegment#1#2{\xy@@{\enter@\cfromthec@}%
 \POS#1\relax
 \xy@@{\edef\tmp@{\cmergethecz@}\leave@}%
 \ifcase#2\xy@@{\setupDirection@ \swap@ \tmp@ \infinitize@-\swap@}%
 \else \xy@@{\tmp@ \setupDirection@ \infinitize@+}\fi}
\xydef@\arcomponent@{%
 \ifx ^\next \toks@ii={^}\DN@ ^{\xyFN@\arcomponent@i}%
 \else\ifx _\next \toks@ii={_}\DN@ _{\xyFN@\arcomponent@i}%
 \else\ifx 1\next \toks@ii={1}\DN@ 1{\xyFN@\arcomponent@i}%
 \else\ifx 2\next \toks@ii={2}\DN@ 2{\xyFN@\arcomponent@i}%
 \else\ifx 3\next \toks@ii={3}\DN@ 3{\xyFN@\arcomponent@i}%
 \else\ifx \bgroup\next \expandafter\toks@ii\expandafter{\arvariant@@}%
 \let\next@=\arcomponent@i
 \else\ifx *\next \DN@*##1##{\arcomponent@ii{##1}}%
 \else \expandafter\toks@ii\expandafter{\arvariant@@}\toks@={}%
 \let\next@=\arcomponenttype@@
 \fi\fi\fi\fi\fi\fi\fi
 \next@}
\xydef@\arcomponent@i#1{\toks@={#1}\arcomponent@x}
\xydef@\arcomponent@ii#1#2{\toks@={*#1{#2}}\xyFN@\arcomponent@@}
\xydef@\artip@{%
 \addGT@\ifx\next \addGT@\addtotoks@ \addGT@\DN@{\xyFN@\artip@}%
 \else\addLT@\ifx\next \addLT@\addtotoks@ \addLT@\DN@{\xyFN@\artip@}%
 \else\ifx (\next \addtotoks@(\DN@({\xyFN@\artip@}%
 \else\ifx )\next \addtotoks@)\DN@){\xyFN@\artip@}%
 \else\ifx |\next \addtotoks@|\DN@|{\xyFN@\artip@}%
 \else\addLQ@\ifx\next \addLQ@\addtotoks@ \addLQ@\DN@{\xyFN@\artip@}%
 \else\addRQ@\ifx\next \addRQ@\addtotoks@ \addRQ@\DN@{\xyFN@\artip@}%
 \else\addPLUS@\ifx \next \addPLUS@\addtotoks@ \addPLUS@\DN@{\xyFN@\artip@}%
 \else\ifx /\next \addtotoks@/\DN@/{\xyFN@\artip@}%
 \else\ifcat A\noexpand\next \DN@##1{\addtotoks@{##1}\xyFN@\artip@}%
 \else\ifx\space@\next \addtotoks@{ }\expandafter\DN@\space{\xyFN@\artip@}%
 \else \let\next@=\arcomponent@x
 \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi \next@}
\xydef@\arconn@{%
 \addDASH@\ifx\next \addDASH@\addtotoks@ \addDASH@\DN@{\xyFN@\arconn@}%
 \else\addEQ@\ifx\next \addEQ@\addtotoks@ \addEQ@\DN@{\xyFN@\arconn@}%
 \ifx\arvariant@@\empty \def\arvariant@@{2}\fi
 \else\addDOT@\ifx\next \addDOT@\addtotoks@ \addDOT@\DN@{\xyFN@\arconn@}%
 \else\ifx :\next \addtotoks@:\DN@:{\xyFN@\arconn@}%
 \ifx\arvariant@@\empty \def\arvariant@@{2}\fi
 \else\ifx ~\next \addtotoks@~\DN@~{\xyFN@\arconn@}%
 \else \let\next@=\arcomponent@x
 \fi\fi\fi\fi\fi \next@}
\xydef@\arcomponent@x{%
 \DN@##1{\toks@=\expandafter{\the\toks@ii{##1}}}%
 \expandafter\next@\expandafter{\the\toks@}%
 \xyFN@\arcomponent@@}
\xydef@\arr@curveslash/#1/{\expandafter\arr@curve\arr@slashing{#1}}
{\xyuncatcodes \gdef\next#1{{**{} ?+/#1/+/#1/ @+c}}}
\xylet@\arr@slashing=\next
\xydef@\arr@curve#1{\curve@check
 \setcurvearrowinit@\arinit@@{#1}%
 \setcurvearrowexit@\arexit@@
 \DN@##1{\def\arstem@@{*\crvs##1}}%
 \expandafter\next@\expandafter{\arstem@@}%
 \xyFN@\arr@}
{\xyuncatcodes \gdef\next#1#2{\def#1{\save @(,#2\restore}}}
\xylet@\setcurvearrowinit@=\next
{\xyuncatcodes \gdef\next#1{\def#1{\POS @i @) }}}
\xylet@\setcurvearrowexit@=\next
\xydef@\curve@check{%
 \xyerror@{Formation @<vector> only available when curve extension loaded}{}}
\xywithoption{curve}{\let\curve@check=\relax}
\xydef@\arr@modifiers#1{\def\armodifiers@@{#1}\xyFN@\arr@}
\xyendinput