\begin{tabbing} (\=(((((D 7) \+ \\[0ex]CollapseTHEN (With $x$ (D 0)))$\cdot$) \\[0ex]CollapseTHENM (HypBackchain))$\cdot$) \\[0ex] \\[0ex]CollapseTHEN ((Auto\_aux (first\_nat 1:n) ((first\_nat 1:n),(first\_nat 3:n)) (first\_tok :t \-\\[0ex]) inil\_term)))$\cdot$ \end{tabbing}