fact: Definition hom_third_isomorphism : Homomorphism (A/Ψ/Θ) (A/Φ) := transport (λ X, Homomorphism X (A/Φ)) path_quotient_algebras_third_surjection (hom_first_isomorphism_surjection hom_third_surjection).
imports: Colimits.Quotient Classes.interfaces.canonical_names Classes.theory.ua_quotient_algebra Classes.theory.ua_isomorphic Classes.theory.ua_first_isomorphism