fact: Fixpoint prodn (T:Type) (n:nat) : Type := match n with | 0 => unit | S p => (T * prodn T p)%type end.
imports: Coq(RelationClasses Setoid Morphisms SetoidList Mergesort Permutation) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq fintype) mathcomp(bigop path) RegexpBrzozowski(glue)