<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 12px; font-family: 'Century Gothic', sans-serif;"><div>My system has installed:</div><div><br></div><div>\usepackage[all]{xy}</div><div>\usepackage{tikz-cd}</div><div><br></div><div>My LaTeX program includes code statements of the type,</div><div><br></div><div>\begin{equation}</div><div>\xymatrix {A \ar[r]^f & B \ar[r]^{{\Phi} & H }</div><div>\end{equation}</div><div><br></div><div>On compiling the LaTeX program the error message on console is:</div><div><br></div><div>(/usr/local/texlive/2013/texmf-dist/tex/generic/pgf/frontendlayer/tikz/libraries/tikzlibrarymatrix.code.tex)) (./Definitions.tex</div><div><br></div><div>./Definitions.tex:32: LaTeX Error: Command \l already defined</div><div> Or name \end… illegal, see p.192 of manual.</div><div><br></div><div>See the LaTeX manual or LaTeX Companion for explanation.</div><div>Type H<return> for immediate help.</div><div>L l.32 \newcommand{\l}{\v(1)}</div><div>?</div><div><br></div><div>Observation: Upon pressing <return> following the above prompt, the program runs to the end and renders the graph correctly. However I must do this every time I compile my (long) program. This intermediate manual intervention is annoying and I would like to automate the compilation.</div><div><br></div><div>Question: What could I possibly do or go to remove the conflicting definition?</div><div><br></div><div><br></div></body></html>