\begin{tabbing} REF, NoConds \\[0ex]RepeatFor \$n ($a$) \\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=(if (((first\_nat \$n:n)) = 0) then (Repeat ($a$)) else (RepeatFor (first\_nat \$n:n) ($a$)))\+ \\[0ex]$\cdot$ \- \end{tabbing}