fact: Definition def_third_surjection (s : Sort σ) : (A/Ψ) s → (A/Φ) s := Quotient_rec (Ψ s) _ (class_of (Φ s)) (third_surjecton_well_def s).
imports: Colimits.Quotient Classes.interfaces.canonical_names Classes.theory.ua_quotient_algebra Classes.theory.ua_isomorphic Classes.theory.ua_first_isomorphism