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Theorem fneq2 5409
Description: Equality theorem for function predicate with domain. (Contributed by NM, 1-Aug-1994.)
Assertion
Ref Expression
fneq2 (𝐴 = 𝐵 → (𝐹 Fn 𝐴𝐹 Fn 𝐵))

Proof of Theorem fneq2
StepHypRef Expression
1 eqeq2 2239 . . 3 (𝐴 = 𝐵 → (dom 𝐹 = 𝐴 ↔ dom 𝐹 = 𝐵))
21anbi2d 464 . 2 (𝐴 = 𝐵 → ((Fun 𝐹 ∧ dom 𝐹 = 𝐴) ↔ (Fun 𝐹 ∧ dom 𝐹 = 𝐵)))
3 df-fn 5320 . 2 (𝐹 Fn 𝐴 ↔ (Fun 𝐹 ∧ dom 𝐹 = 𝐴))
4 df-fn 5320 . 2 (𝐹 Fn 𝐵 ↔ (Fun 𝐹 ∧ dom 𝐹 = 𝐵))
52, 3, 43bitr4g 223 1 (𝐴 = 𝐵 → (𝐹 Fn 𝐴𝐹 Fn 𝐵))
Colors of variables: wff set class
Syntax hints:  wi 4  wa 104  wb 105   = wceq 1395  dom cdm 4718  Fun wfun 5311   Fn wfn 5312
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1493  ax-gen 1495  ax-4 1556  ax-17 1572  ax-ext 2211
This theorem depends on definitions:  df-bi 117  df-cleq 2222  df-fn 5320
This theorem is referenced by:  fneq2d  5411  fneq2i  5415  feq2  5456  foeq2  5544  f1o00  5607  eqfnfv2  5732  tfr0dm  6466  tfrlemisucaccv  6469  tfrlemi1  6476  tfrlemi14d  6477  tfrexlem  6478  tfr1onlemsucfn  6484  tfr1onlemsucaccv  6485  tfr1onlembxssdm  6487  tfr1onlembfn  6488  tfr1onlemaccex  6492  tfr1onlemres  6493  ixpeq1  6854  0fz1  10237
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