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Theorem feq3 5941
 Description: Equality theorem for functions. (Contributed by NM, 1-Aug-1994.)
Assertion
Ref Expression
feq3 (𝐴 = 𝐵 → (𝐹:𝐶𝐴𝐹:𝐶𝐵))

Proof of Theorem feq3
StepHypRef Expression
1 sseq2 3590 . . 3 (𝐴 = 𝐵 → (ran 𝐹𝐴 ↔ ran 𝐹𝐵))
21anbi2d 736 . 2 (𝐴 = 𝐵 → ((𝐹 Fn 𝐶 ∧ ran 𝐹𝐴) ↔ (𝐹 Fn 𝐶 ∧ ran 𝐹𝐵)))
3 df-f 5808 . 2 (𝐹:𝐶𝐴 ↔ (𝐹 Fn 𝐶 ∧ ran 𝐹𝐴))
4 df-f 5808 . 2 (𝐹:𝐶𝐵 ↔ (𝐹 Fn 𝐶 ∧ ran 𝐹𝐵))
52, 3, 43bitr4g 302 1 (𝐴 = 𝐵 → (𝐹:𝐶𝐴𝐹:𝐶𝐵))
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ↔ wb 195   ∧ wa 383   = wceq 1475   ⊆ wss 3540  ran crn 5039   Fn wfn 5799  ⟶wf 5800 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590 This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-clab 2597  df-cleq 2603  df-clel 2606  df-in 3547  df-ss 3554  df-f 5808 This theorem is referenced by:  feq23  5942  feq3d  5945  fun2  5980  fconstg  6005  f1eq3  6011  mapvalg  7754  mapsn  7785  cantnff  8454  axdc4uz  12645  supcvg  14427  lmff  20915  txcn  21239  lmmbr  22864  iscmet3  22899  dvcnvrelem2  23585  itgsubstlem  23615  umgrislfupgr  25789  isumgra  25844  wlks  26047  wlkcompim  26054  wlkelwrd  26058  iseupa  26492  isgrpo  26735  vciOLD  26800  isvclem  26816  nmop0h  28234  sitgaddlemb  29737  sitmcl  29740  cvmliftlem15  30534  mtyf  30703  matunitlindflem1  32575  sdclem1  32709  k0004lem1  37465  mapsnd  38383  stoweidlem57  38950  usgrislfuspgr  40414  1wlkv0  40859
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