2

I would like to plot an arrow without head AND curved. I can achieve both goals separately but not on the same arrow:

\documentclass{minimal}
\usepackage{amsmath}
\usepackage[all]{xy}

\begin{document}

    \begin{equation}
    \xymatrix{
    &G\ar@{-}[d]^{\le}\ar@{-}[ddl]_{\le}\ar@/^/[ddr]^{\triangleleft}&\\
    &HN\ar@{-}[dl]_{\le}\ar@{-}[dr]^{\triangleleft}&\\
    H\ar@{-}[dr]_{\triangleleft}&&N\ar@{-}[dl]^{\le}\\
    &H\cap N&
    }
    \end{equation}

\end{document}

I would like to merge

\ar@{-}[ddr]^{\triangleleft}

and 

\ar@/^/[ddr]^{\triangleleft}
PeptideChain
  • 1,335

1 Answers1

4

You need an extra @. (And by the way, please don't use minimal).

\documentclass{standalone}
\usepackage{amsmath}
\usepackage[all]{xy}
\begin{document}
    \xymatrix{
        &G\ar@{-}[d]^{\le}\ar@{-}[ddl]_{\le}\ar@{-}@/^/[ddr]^{\triangleleft}&\\
    &HN\ar@{-}[dl]_{\le}\ar@{-}[dr]^{\triangleleft}&\\
    H\ar@{-}[dr]_{\triangleleft}&&N\ar@{-}[dl]^{\le}\\
    &H\cap N&
    }
\end{document}

enter image description here

For reference see the answer to exercise 9 in section 2.3 of xyguide

Thruston
  • 42,268