Theorem feq123d 5037

Description: Equality deduction for functions. (Contributed by Paul Chapman, 22-Jun-2011.)

Hypotheses

Ref	Expression
feq12d.1	⊢ (𝜑 → 𝐹 = 𝐺)
feq12d.2	⊢ (𝜑 → 𝐴 = 𝐵)
feq123d.3	⊢ (𝜑 → 𝐶 = 𝐷)

Assertion

Ref	Expression
feq123d	⊢ (𝜑 → (𝐹:𝐴⟶𝐶 ↔ 𝐺:𝐵⟶𝐷))

Proof of Theorem feq123d

Step	Hyp	Ref	Expression
1		feq12d.1	. . 3 ⊢ (𝜑 → 𝐹 = 𝐺)
2		feq12d.2	. . 3 ⊢ (𝜑 → 𝐴 = 𝐵)
3	1, 2	feq12d 5036	. 2 ⊢ (𝜑 → (𝐹:𝐴⟶𝐶 ↔ 𝐺:𝐵⟶𝐶))
4		feq123d.3	. . 3 ⊢ (𝜑 → 𝐶 = 𝐷)
5		feq3 5032	. . 3 ⊢ (𝐶 = 𝐷 → (𝐺:𝐵⟶𝐶 ↔ 𝐺:𝐵⟶𝐷))
6	4, 5	syl 14	. 2 ⊢ (𝜑 → (𝐺:𝐵⟶𝐶 ↔ 𝐺:𝐵⟶𝐷))
7	3, 6	bitrd 177	1 ⊢ (𝜑 → (𝐹:𝐴⟶𝐶 ↔ 𝐺:𝐵⟶𝐷))

Syntax hints:   → wi 4   ↔ wb 98   = wceq 1243  ⟶wf 4898

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-10 1396  ax-11 1397  ax-i12 1398  ax-bndl 1399  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-3an 887  df-tru 1246  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-nfc 2167  df-v 2559  df-un 2922  df-in 2924  df-ss 2931  df-sn 3381  df-pr 3382  df-op 3384  df-br 3765  df-opab 3819  df-rel 4352  df-cnv 4353  df-co 4354  df-dm 4355  df-rn 4356  df-fun 4904  df-fn 4905  df-f 4906

This theorem is referenced by:  feq123  5038  feq23d  5042