fact: Structure is_finite (T : eqType) (P : pred T) := IsFinite { seq_of_is_finite :> seq T; _ : uniq seq_of_is_finite; _ : forall x, x \in seq_of_is_finite = P x; }.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrnat eqtype ssrfun seq) mathcomp(choice path finset finfun fintype bigop)