Theorem f1eq2 5113

Description: Equality theorem for one-to-one functions. (Contributed by NM, 10-Feb-1997.)

Assertion

Ref	Expression
f1eq2	⊢ (𝐴 = 𝐵 → (𝐹:𝐴–1-1→𝐶 ↔ 𝐹:𝐵–1-1→𝐶))

Proof of Theorem f1eq2

Step	Hyp	Ref	Expression
1		feq2 5056	. . 3 ⊢ (𝐴 = 𝐵 → (𝐹:𝐴⟶𝐶 ↔ 𝐹:𝐵⟶𝐶))
2	1	anbi1d 453	. 2 ⊢ (𝐴 = 𝐵 → ((𝐹:𝐴⟶𝐶 ∧ Fun ◡𝐹) ↔ (𝐹:𝐵⟶𝐶 ∧ Fun ◡𝐹)))
3		df-f1 4931	. 2 ⊢ (𝐹:𝐴–1-1→𝐶 ↔ (𝐹:𝐴⟶𝐶 ∧ Fun ◡𝐹))
4		df-f1 4931	. 2 ⊢ (𝐹:𝐵–1-1→𝐶 ↔ (𝐹:𝐵⟶𝐶 ∧ Fun ◡𝐹))
5	2, 3, 4	3bitr4g 221	1 ⊢ (𝐴 = 𝐵 → (𝐹:𝐴–1-1→𝐶 ↔ 𝐹:𝐵–1-1→𝐶))

Syntax hints:   → wi 4   ∧ wa 102   ↔ wb 103   = wceq 1285  ^◡ccnv 4364  Fun wfun 4920  ⟶wf 4922  –1-1→wf1 4923

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1377  ax-gen 1379  ax-4 1441  ax-17 1460  ax-ext 2064

This theorem depends on definitions:  df-bi 115  df-cleq 2075  df-fn 4929  df-f 4930  df-f1 4931

This theorem is referenced by:  f1oeq2  5143  f1eq123d  5146  brdomg  6288