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Theorem fneq2 5416
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 5327 . 2 (𝐹 Fn 𝐴 ↔ (Fun 𝐹 ∧ dom 𝐹 = 𝐴))
4 df-fn 5327 . 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 4723  Fun wfun 5318   Fn wfn 5319
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 5327
This theorem is referenced by:  fneq2d  5418  fneq2i  5422  feq2  5463  foeq2  5553  f1o00  5616  eqfnfv2  5741  tfr0dm  6483  tfrlemisucaccv  6486  tfrlemi1  6493  tfrlemi14d  6494  tfrexlem  6495  tfr1onlemsucfn  6501  tfr1onlemsucaccv  6502  tfr1onlembxssdm  6504  tfr1onlembfn  6505  tfr1onlemaccex  6509  tfr1onlemres  6510  ixpeq1  6873  0fz1  10270
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