\begin{tabbing}
(\=(((UnivCD) \+
\\[0ex]C\=ollapseTHENM (Backchain \+
\\[0ex]
\\[0ex]``sq\_stable\_\_from\_stable stable\_\_from\_decidable``))$\cdot$) 
\-\\[0ex]CollapseTHEN (
\-\\[0ex](Auto\_aux (first\_nat 1:n) ((first\_nat 1:n),(first\_nat 3:n)) (first\_tok :t) inil\_term)))$\cdot$
\end{tabbing}