fact: Definition pred_scalar P F : gset regexp := fun G => exists e, P e /\ similar G (Conc e F).
imports: Coq(RelationClasses Setoid Morphisms Permutation) Coq(SetoidList Mergesort Orders) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq fintype) mathcomp(bigop path) RegLang(languages) RegexpBrzozowski(glue gfinset regexp)