proposition: Lemma hrel_of_morphism (A B : finType) : morphism (BDL+STR+CNV+DIV) (@hrel_of A B).
proof: Proof. split; try done; try hrel_prop. move => e1 e2 H x y. apply/eq_bool_iff. exact: H. Qed.
imports: Setoid Morphisms kat normalisation rewriting kat_tac comparisons rel relalg boolean mathcomp(all_ssreflect)