\begin{tabbing}
let $a$,$b$,$c$,$d$,$e$,$f$,$g$,$h$ = $u$ in 
\\[0ex]$v$($a$;$b$;$c$;$d$;$e$;$f$;$g$;$h$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=let $a$,${\it zz}_{1}$ = $u$\+
\\[0ex]in
\\[0ex]let $b$,${\it zz}_{2}$ = ${\it zz}_{1}$
\\[0ex]in
\\[0ex]let $c$,${\it zz}_{3}$ = ${\it zz}_{2}$
\\[0ex]in
\\[0ex]let $d$,${\it zz}_{4}$ = ${\it zz}_{3}$
\\[0ex]in
\\[0ex]let $e$,${\it zz}_{5}$ = ${\it zz}_{4}$ in let $f$,${\it zz}_{6}$ = ${\it zz}_{5}$ in let $g$,$h$ = ${\it zz}_{6}$ in $v$($a$;$b$;$c$;$d$;$e$;$f$;$g$;$h$)
\-
\end{tabbing}