\begin{tabbing}
(\% do simple nat induction\% 
\\[0ex](\=(((BLemma `nat\_ind\_a`) \+
\\[0ex]CollapseTHENM (RepD))$\cdot$) 
\\[0ex]
\\[0ex]CollapseTHENA ((Auto\_aux (first\_nat 1:n) ((first\_nat 1:n),(first\_nat 3:n)) (first\_tok :t
\-\\[0ex]) inil\_term)))$\cdot$)
\end{tabbing}