\begin{tabbing}
(\=(((((((D 0) \+
\\[0ex]CollapseTHEN (RW assert\_pushdownC ({-}1)))$\cdot$) 
\\[0ex]CollapseTHENA (
\-\\[0ex](\=Auto\_aux (first\_nat 1:n) ((first\_nat 1:n),(first\_nat 3:n)) (first\_tok :t) inil\_term)))$\cdot$)\+
\\[0ex]
\\[0ex]CollapseTHEN (HypSubst ({-}1) ({-}3)))$\cdot$) 
\\[0ex]CollapseTHEN ((Auto\_aux (first\_nat 1:n
\-\\[0ex]) ((first\_nat 1:n),(first\_nat 3:n)) (first\_tok :t) inil\_term)))$\cdot$
\end{tabbing}