fact: Definition pack (eb0 : Equality.mixin_of T) (m0 : mixin_of (EqType T eb0)) := fun m & phant_id m0 m => Pack (@Class T eb0 m).
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq bigop fintype finset) pcm(options axioms prelude seqperm pred seqext)