fact: Definition tuple_pad k n (l:n.-tuple 'I_3) (H: n <= k) := (tcast (size_tuple_padl l H) (in_tuple (tuple_padl k l))).
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq choice fintype order bigop ssralg) mathcomp(div ssrnum ssrint rat prime path binomial) mathcomp(tuple finset) gaia(fibm)