proposition: Lemma inl_subsets_prop S M (H:inl_subfam_hyp S M) : inductive_system_on (inductive_system_subsets H) M (isI S) (isr S) (inl_subfam_fct S M).
proof: Proof. done. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)