Theorem feq2 6718

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 6661	. . 3 ⊢ (𝐴 = 𝐵 → (𝐹 Fn 𝐴 ↔ 𝐹 Fn 𝐵))
2	1	anbi1d 631	. 2 ⊢ (𝐴 = 𝐵 → ((𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶) ↔ (𝐹 Fn 𝐵 ∧ ran 𝐹 ⊆ 𝐶)))
3		df-f 6567	. 2 ⊢ (𝐹:𝐴⟶𝐶 ↔ (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶))
4		df-f 6567	. 2 ⊢ (𝐹:𝐵⟶𝐶 ↔ (𝐹 Fn 𝐵 ∧ ran 𝐹 ⊆ 𝐶))
5	2, 3, 4	3bitr4g 314	1 ⊢ (𝐴 = 𝐵 → (𝐹:𝐴⟶𝐶 ↔ 𝐹:𝐵⟶𝐶))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1537   ⊆ wss 3963  ran crn 5690   Fn wfn 6558  ⟶wf 6559

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1792  ax-4 1806  ax-5 1908  ax-6 1965  ax-7 2005  ax-9 2116  ax-ext 2706

This theorem depends on definitions:  df-bi 207  df-an 396  df-ex 1777  df-cleq 2727  df-fn 6566  df-f 6567

This theorem is referenced by:  feq23  6720  feq2d  6723  feq2i  6729  f00  6791  f0dom0  6793  f1eq2  6801  fressnfv  7180  poseq  8182  soseq  8183  mapvalg  8875  fsetexb  8903  map0g  8923  ac6sfi  9318  cofsmo  10307  axcc4dom  10479  ac6sg  10526  isghm  19246  isghmOLD  19247  pjdm2  21749  cmpcovf  23415  ulmval  26438  elno2  27714  noreson  27720  measval  34179  isrnmeas  34181  bj-finsumval0  37268  mbfresfi  37653  sn-isghm  42660  dfno2  43418  stoweidlem62  46018  hoidmvval0b  46546  vonioo  46638  vonicc  46641  f102g  48682  f1mo  48683