fact: Definition merge_union_K: merge_seq (F ⊎ K) h ≃ merge_seq F union_K_pairs := Iso hom_merge_union_K.
imports: Coq(Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij) GraphTheory(equiv digraph setoid_bigop structures)