\begin{tabbing}
(\% Desired main subgoal with inductive hyp 9 \% 
\\[0ex](\=(BHyp 7) \+
\\[0ex]CollapseTHEN (
\-\\[0ex](Auto\_aux (first\_nat 1:n) ((first\_nat 1:n),(first\_nat 4:n)) (first\_tok :t) inil\_term)))$\cdot$)
\end{tabbing}