proposition: Lemma prune_D1 : D1 (S `|` T).
proof: Proof. move => C inST s inC. apply: sub_has_dom (prune_D1_strong inC inST). exact/subP. Qed.
imports: Relations Lia mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert sltype) CompDecModal.Kstar(Kstar_def demo hilbert_ref gen_def)