| napply (H4 K2)]##]
nqed.
-unification hint 0 ≔ A,B ⊢ fun21 … and_morphism A B ≡ And A B.
+(*unification hint 0 ≔ A,B ⊢ fun21 … and_morphism A B ≡ And A B.*)
+unification hint 0 ≔ A,B ⊢ fun21 … (mk_binary_morphism1 … And (prop21 … and_morphism)) A B ≡ And A B.
+
+(*nlemma test: ∀A,A',B: CProp[0]. A=A' → (B ∨ A) = B → (B ∧ A) ∧ B.
+ #A; #A'; #B; #H1; #H2;
+ napply (. ((#‡H1)‡H2^-1)); nnormalize;
+nqed.*)
+
(*nlemma test: ∀A,A',B: CProp[0]. A=A' → (B ∨ A) = B → (B ∧ A) ∧ B.
#A; #A'; #B; #H1; #H2;