\begin{tabbing} (\=(((Unfold `sq\_stable` 5) \+ \\[0ex]CollapseTHEN (BackThruHyp 5))$\cdot$) \\[0ex]CollapseTHENA ( \-\\[0ex](Auto\_aux (first\_nat 1:n) ((first\_nat 1:n),(first\_nat 4:n)) (first\_tok :t) inil\_term)))$\cdot$ \end{tabbing}