proposition: Lemma href_R2 C s : href (s^- |` R C) -> href (fAX s^- |` C).
proof: Proof. rewrite /href. do 2 rewrite -> andU,bigA1. rewrite -[_ (s^-)]/(~~: s) -[_ (fAX s^-)]/(~~: AX s) => /= H. rewrite -> dmAX,box_request. rewrite <- axDF. rewrite <- H. rule axAcase. apply axDBD. Qed.
imports: Lia mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert sltype) CompDecModal.K(K_def demo)