fact: Fixpoint INA (l : seq A) (a : A) : Prop := match l with | [::] => False | hd :: tl => eqA a hd \/ INA tl a end.
imports: Coq(RelationClasses Setoid Morphisms SetoidList Mergesort Permutation) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq fintype) mathcomp(bigop path) RegexpBrzozowski(glue)