In a graph how to put infinity on the edgelabels? [closed]

Question

So I am making Digraphs in tikz and want to put infinity as edge label but im getting an error. I got no error when i set the label under the vertices to infinity.

\documentclass[a4paper,11pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{listingsutf8}
\usepackage{multicol}
\usepackage{graphicx}
\usepackage{wrapfig}
\usepackage[retainorgcmds]{IEEEtrantools}
\usepackage{tikz}
\usetikzlibrary{arrows,decorations.pathmorphing,backgrounds,positioning,fit,matrix} 
\usepackage{wasysym}
\usepackage{float}



\usepackage{listings,relsize} 
\lstloadlanguages{R} 
\lstset{language=R,basicstyle=\smaller[1],
commentstyle=\rmfamily\smaller, showstringspaces=false,breaklines=true} 
\lstset{escapeinside={(*}{*)}} 

\begin{document}
\tikzstyle{vertex}=[circle,fill=black!25,minimum size=15pt,inner sep=0pt] 
\tikzstyle{selectedvertex} = [vertex, fill=red!24] 
\tikzstyle{edge} = [draw,thick,-] 
\tikzstyle{arc}= [draw,thick,->,shorten >=1pt,>=stealth'] 
\tikzstyle{arcl} = [draw,thick,->,shorten>=1pt,>=stealth',bend left=25] 
\tikzstyle{arcr} = [draw,thick,->,shorten >=1pt,>=stealth']
\tikzstyle{rpath}=[draw, thick,->,shorten >=1pt,>=stealth',red, opacity=0.4]
\tikzstyle{weight} = [font=\small] 
\tikzstyle{selected edge} = [draw,line width=5pt,-,red!50]
\tikzstyle{ignored edge} = [draw,line width=5pt,-,black!20] 
\newcommand*{\vpointer}{\vcenter{\hbox{\scalebox{2}{\Huge\pointer}}}}
\def\Arrow{\raisebox{3\height}{\scalebox{3}{$\Rightarrow$}}}


\begin{figure} [H]
    \begin{tikzpicture}[width=0.3\textwidth, auto,swap] 
      % First we draw the vertices  
        \foreach \pos/\name/\weight in
    {{(0,1)/s/-2},
    {(1,4)/1/1},
    {(4.5,4)/2/-1},
    {(4,0)/3/2},
    {(5,1.5)/t/0},
    {(2.5,0)/s'/-$\infty$},
    {(0.5,6)/t'/0}}
            \node[vertex,label=below:\weight] (\name) at \pos {$\name$};
        % Connect vertices with edges and draw weights
        \foreach \source/ \dest /\weight in { 
s/1/2, 1/2/2,1/3/2,2/3/3, 3/t/3 , t/s/$\infty$, s/t'/2,2/t'/1,s'/1/1,s'/3/2
      }
    \path[arcr] (\source) -- node[weight] {$\weight$} (\dest); 
\end{tikzpicture} 
\end{figure}

The first -$\infty$ works fine but at the line with the edges the infinity won't work. I get the error at the line with \path[arcr] and I don't know how to copi paste the error from kile :S.

It does show the infinity sign as wanted but right behind it it writes "pgf@stop"

Hope you can help : )