proposition: Lemma ssim1_refl : reflexive ssim1.
proof: Proof. rewrite /ssim1 => r. by rewrite -ssublr !ssubl_refl. Qed.
imports: Coq(RelationClasses Setoid Morphisms Permutation) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq fintype) mathcomp(bigop path) RegLang(languages) RegexpBrzozowski(regexp finite_der equiv)