Problem with \xymatrix in svjour3 [closed]

Question

I attempt to compile the following

\newcommand{\arb}[1]{\ar@<-.15ex>[#1]\ar@<.15ex>[#1]\ar@<-.075ex>[#1]\ar@<.075ex>[#1]\ar[#1]}
\[\xymatrix{
& \arb{rr}^<<<<{}="1"^g & & \arb{dr}_<<<<{}="5"^f &\\
\arb{ur}^h \ar[rr]^>>>>>>{}="2"_>>>>>>{}="3"^k \arb{dr}_c &\ar[ur]^d\ar[dr]_e & &\\
& \arb{rr}^<<<<{}="4"_b & &\arb{ur}^<<<<{}="6"_a &
\ar@{=>}"1";"2"^{T}
\ar@{=>}"3";"4"^{V}
\ar@/_.6pc/@{=>}"5";"6"^{U}
}
\;\qquad
\xymatrix{
&\arb{rr}^>>>>>>{}="1"^g\ar[dr] & & \arb{dr}^f &\\
\arb{ur}_>>>>{}="5"^h \arb{dr}^>>>>{}="6"_c & &\ar[rr]^<<<<{}="2"_<<<<{}="3"& &\\
& \arb{rr}^>>>>>>{}="4"_b  \ar[ur]& &\arb{ur}_a &
\ar@{=>}"1";"2"^{A} 
\ar@{=>}"3";"4"^{C} 
\ar@/^.6pc/@{=>}"5";"6"^{B}}
\]

and I get the error

[2][3]<xymatrix
!Missing $ inserted.
<inserted text>
    $
l.157 }

When I hit "go to error" the space \;\qquad is highlighted. I'm using the header

\documentclass[draft]{svjour3}
\usepackage{amscd,amssymb} %amsxtra,amsmath}
\usepackage[pdftex]{hyperref}
\usepackage{natbib}
\input xy
\xyoption{all}
\usepackage[v2,cmtip]{xy}

Please help. I'm trying to prepare the manuscript for submission. Thanks in advance!

Answer 1

Processing your example (I don't have the svjour3 class, so I used article) code one gets the error message

 ! Xy-pic error: in entry "1,4": No [dr] (is "2,5") from here.
 \xyerror@ ...#2}\fi \errmessage {Xy-pic error: #1}

which indicates the problem; on entry 1.4 you declared an arrow going down and to the right (to entry 2.5), and no entry 2.5 exists. Adding an extra & character to the second row solves the problem :

\documentclass{article}
\usepackage{amscd,amssymb} %amsxtra,amsmath}
\usepackage[pdftex]{hyperref}
\usepackage{natbib}
\usepackage[all,v2,cmtip]{xy}
\begin{document}

\newcommand{\arb}[1]{\ar@<-.15ex>[#1]\ar@<.15ex>[#1]\ar@<-.075ex>[#1]\ar@<.075ex>[#1]\ar[#1]}
\[
\xymatrix{
& \arb{rr}^<<<<{}="1"^g & & \arb{dr}_<<<<{}="5"^f &\\
\arb{ur}^h \ar[rr]^>>>>>>{}="2"_>>>>>>{}="3"^k \arb{dr}_c 
   & &\ar[ur]^d\ar[dr]_e & & \\
& \arb{rr}^<<<<{}="4"_b & &\arb{ur}^<<<<{}="6"_a &
\ar@{=>}"1";"2"^{T}
\ar@{=>}"3";"4"^{V}
\ar@/_.6pc/@{=>}"5";"6"^{U}
}
\;\qquad
\xymatrix{
&\arb{rr}^>>>>>>{}="1"^g\ar[dr] & & \arb{dr}^f &\\
\arb{ur}_>>>>{}="5"^h \arb{dr}^>>>>{}="6"_c & &\ar[rr]^<<<<{}="2"_<<<<{}="3"& &\\
& \arb{rr}^>>>>>>{}="4"_b  \ar[ur]& &\arb{ur}_a &
\ar@{=>}"1";"2"^{A} 
\ar@{=>}"3";"4"^{C} 
\ar@/^.6pc/@{=>}"5";"6"^{B}}
\]
\end{document}