proposition: Lemma RU a (C C' : clause) : R a (C `|` C') = (R a C `|` R a C').
proof: Proof. by rewrite /R sepU fimsetU. Qed.
imports: Relations Lia Setoid Morphisms mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert sltype rewrite_inequality fset_tac)