Theorem feq2 6681

Description: Equality theorem for functions. (Contributed by NM, 1-Aug-1994.)

Assertion

Ref	Expression
feq2	⊢ (𝐴 = 𝐵 → (𝐹:𝐴⟶𝐶 ↔ 𝐹:𝐵⟶𝐶))

Proof of Theorem feq2

Step	Hyp	Ref	Expression
1		fneq2 6624	. . 3 ⊢ (𝐴 = 𝐵 → (𝐹 Fn 𝐴 ↔ 𝐹 Fn 𝐵))
2	1	anbi1d 643	. 2 ⊢ (𝐴 = 𝐵 → ((𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶) ↔ (𝐹 Fn 𝐵 ∧ ran 𝐹 ⊆ 𝐶)))
3		df-f 6537	. 2 ⊢ (𝐹:𝐴⟶𝐶 ↔ (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶))
4		df-f 6537	. 2 ⊢ (𝐹:𝐵⟶𝐶 ↔ (𝐹 Fn 𝐵 ∧ ran 𝐹 ⊆ 𝐶))
5	2, 3, 4	3bitr4g 317	1 ⊢ (𝐴 = 𝐵 → (𝐹:𝐴⟶𝐶 ↔ 𝐹:𝐵⟶𝐶))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   = wceq 1570   ⊆ wss 3899  ran crn 5656   Fn wfn 6528  ⟶wf 6529

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-9 2155  ax-ext 2732

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1813  df-cleq 2752  df-fn 6536  df-f 6537

This theorem is used by:  feq23  6683  feq2d  6686  feq2i  6694  f00  6757  f0dom0  6759  f1eq2  6767  fressnfv  7157  poseq  8156  soseq  8157  mapvalg  8835  fsetexb  8865  map0g  8891  ac6sfi  9254  cofsmo  10271  axcc4dom  10443  ac6sg  10490  isghm  19343  pjdm2  21924  cmpcovf  23616  ulmval  26616  elno2  27890  noreson  27896  measval  34709  isrnmeas  34711  bj-finsumval0  38037  mbfresfi  38415  sn-isghm  43519  dfno2  44268  relpeq4  45770  stoweidlem62  46890  hoidmvval0b  47418  vonioo  47510  vonicc  47513  f102g  49780  f1mo  49781