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Theorem f1eq2 5196
Description: Equality theorem for one-to-one functions. (Contributed by NM, 10-Feb-1997.)
Assertion
Ref Expression
f1eq2 (𝐴 = 𝐵 → (𝐹:𝐴1-1𝐶𝐹:𝐵1-1𝐶))

Proof of Theorem f1eq2
StepHypRef Expression
1 feq2 5132 . . 3 (𝐴 = 𝐵 → (𝐹:𝐴𝐶𝐹:𝐵𝐶))
21anbi1d 453 . 2 (𝐴 = 𝐵 → ((𝐹:𝐴𝐶 ∧ Fun 𝐹) ↔ (𝐹:𝐵𝐶 ∧ Fun 𝐹)))
3 df-f1 5007 . 2 (𝐹:𝐴1-1𝐶 ↔ (𝐹:𝐴𝐶 ∧ Fun 𝐹))
4 df-f1 5007 . 2 (𝐹:𝐵1-1𝐶 ↔ (𝐹:𝐵𝐶 ∧ Fun 𝐹))
52, 3, 43bitr4g 221 1 (𝐴 = 𝐵 → (𝐹:𝐴1-1𝐶𝐹:𝐵1-1𝐶))
Colors of variables: wff set class
Syntax hints:  wi 4  wa 102  wb 103   = wceq 1289  ccnv 4427  Fun wfun 4996  wf 4998  1-1wf1 4999
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1381  ax-gen 1383  ax-4 1445  ax-17 1464  ax-ext 2070
This theorem depends on definitions:  df-bi 115  df-cleq 2081  df-fn 5005  df-f 5006  df-f1 5007
This theorem is referenced by:  f1oeq2  5229  f1eq123d  5232  brdomg  6445
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