[Tex/LaTex] How to draw this control flow graph using pstricks/tikz

Question

This is just a simplified image of a control flow graph which I want to draw. The boxes contain multiple lines of text/mathematical symbols. And the transitions are all labelled using [] brackets. Could someone tell me how to draw the following?

Answer 1

Something like this (with pstricks)?

\documentclass{article}
\usepackage{array} 
\usepackage{mathtools, amsfonts, amssymb}

\usepackage{pstricks-add}
\usepackage{auto-pst-pdf}

\begin{document}

\begin{center}
  \sffamily\everymath{\scriptstyle}
  \begin{pspicture}
    \psset{arrows=->, arrowinset=0.15, linewidth=0.6pt, nodesep=2pt, labelsep=2pt, colsep=1cm, rowsep=1.5cm, linejoin=1}
    \begin{psmatrix}
      & \ovalnode{S}{\,start\strut\,}\\
      & \ovalnode{A}{\enspace\,A\strut\enspace\,} \\
      \ovalnode{B}{\enspace\,B\strut\enspace\,} & \\
      & \ovalnode{C}{\enspace\,C\strut\enspace\,}\\
    \end{psmatrix}
    \ncline{S}{A}\nbput{\renewcommand\arraystretch{0.8}\begin{tabular}{|>{\footnotesize}l|}\hline Some\\ condition\\\hline\end{tabular}}
    \ncline[]{A}{B}\nbput{\footnotesize[true]}%
    \ncline[]{A}{C}\naput{\footnotesize[false]}%
    \ncline{B}{C}\nbput{\renewcommand\arraystretch{0.8}\begin{tabular}{|>{\footnotesize}l|}\hline Some other\\ condition\\\hline\end{tabular}}
    \ncdiagg[angleA=50, armA=2.4]{C}{A}\nbput{\footnotesize[expression]}%
  \end{pspicture}
\end{center}

\end{document}