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Theorem feq2 6496
Description: Equality theorem for functions. (Contributed by NM, 1-Aug-1994.)
Assertion
Ref Expression
feq2 (𝐴 = 𝐵 → (𝐹:𝐴𝐶𝐹:𝐵𝐶))

Proof of Theorem feq2
StepHypRef Expression
1 fneq2 6445 . . 3 (𝐴 = 𝐵 → (𝐹 Fn 𝐴𝐹 Fn 𝐵))
21anbi1d 631 . 2 (𝐴 = 𝐵 → ((𝐹 Fn 𝐴 ∧ ran 𝐹𝐶) ↔ (𝐹 Fn 𝐵 ∧ ran 𝐹𝐶)))
3 df-f 6359 . 2 (𝐹:𝐴𝐶 ↔ (𝐹 Fn 𝐴 ∧ ran 𝐹𝐶))
4 df-f 6359 . 2 (𝐹:𝐵𝐶 ↔ (𝐹 Fn 𝐵 ∧ ran 𝐹𝐶))
52, 3, 43bitr4g 316 1 (𝐴 = 𝐵 → (𝐹:𝐴𝐶𝐹:𝐵𝐶))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 208  wa 398   = wceq 1537  wss 3936  ran crn 5556   Fn wfn 6350  wf 6351
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1970  ax-7 2015  ax-9 2124  ax-ext 2793
This theorem depends on definitions:  df-bi 209  df-an 399  df-ex 1781  df-cleq 2814  df-fn 6358  df-f 6359
This theorem is referenced by:  feq23  6498  feq2d  6500  feq2i  6506  f00  6561  f0dom0  6563  f1eq2  6571  fressnfv  6922  mapvalg  8416  map0g  8448  ac6sfi  8762  cofsmo  9691  axcc4dom  9863  ac6sg  9910  isghm  18358  pjdm2  20855  cmpcovf  21999  ulmval  24968  measval  31457  isrnmeas  31459  poseq  33095  soseq  33096  elno2  33161  noreson  33167  bj-finsumval0  34570  mbfresfi  34953  stoweidlem62  42367  hoidmvval0b  42892  vonioo  42984  vonicc  42987
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