\foreach \x [count = \xi] in {a,...,e}Was wäre hier die Lösung, um diesen Code der tikz-docu zu kompilieren?
Danke!
\foreach \x [count = \xi] in {a,...,e}\documentclass{article}
\usepackage{tikz}
\begin{document}
\tikz[x=0.75cm,y=0.75cm]
  \foreach \x [count=\xi] in {a,...,e}
    \foreach \y [count=\yi] in {\x,...,e}
      \node [draw, top color=white, bottom color=blue!50, minimum size=0.666cm]
        at (\xi,-\yi) {$\mathstrut\x\y$};
\end{document}