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 643	. 2 ⊢ (𝐴 = 𝐵 → ((𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶) ↔ (𝐹 Fn 𝐵 ∧ ran 𝐹 ⊆ 𝐶)))
3		df-f 6570	. 2 ⊢ (𝐹:𝐴⟶𝐶 ↔ (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶))
4		df-f 6570	. 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 3900  ran crn 5659   Fn wfn 6561  ⟶wf 6562

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 1945  ax-6 2002  ax-7 2043  ax-9 2157  ax-ext 2735

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1813  df-cleq 2755  df-fn 6569  df-f 6570

This theorem is used by:  feq23  6720  feq2d  6723  feq2i  6731  f00  6794  f0dom0  6796  f1eq2  6804  fressnfv  7196  poseq  8212  soseq  8213  mapvalg  8894  fsetexb  8924  map0g  8950  ac6sfi  9313  cofsmo  10386  axcc4dom  10558  ac6sg  10605  isghm  19480  pjdm2  22072  cmpcovf  23764  ulmval  26764  elno2  28068  noreson  28074  measval  34942  isrnmeas  34944  bj-finsumval0  38474  mbfresfi  38852  sn-isghm  43950  dfno2  44690  relpeq4  46201  stoweidlem62  47345  hoidmvval0b  47873  vonioo  47965  vonicc  47968  f102g  50294  f1mo  50295