1 \documentclass{article}
4 \usepackage{amssymb,amsbsy}
7 \settowidth{\MyLength}{machine code}
8 \newcommand{\MyBox}[1]{\makebox[\MyLength][c]{#1}}
9 \begin{psmatrix}[colsep=2,rowsep=0]
11 [name=s0]\MyBox{unsafe source} & [name=s1]\MyBox{safe source} \\[0pt]
12 [name=s00]\MyBox{\tt (.c)} & [name=s11]\MyBox{\tt (.java)} \\[0pt]
16 [name=b0]\MyBox{machine code} & [name=b1]\MyBox{safe bytecode} \\[0pt]
17 [name=b00]\MyBox{\tt (.o)} & [name=b11]\MyBox{\tt (.class)} \\
19 \psset{nodesep=5pt,arrows=->}