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Theorem fneq2 5450
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 2244 . . 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 5360 . 2 (𝐹 Fn 𝐴 ↔ (Fun 𝐹 ∧ dom 𝐹 = 𝐴))
4 df-fn 5360 . 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 1398  dom cdm 4754  Fun wfun 5351   Fn wfn 5352
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 1496  ax-gen 1498  ax-4 1559  ax-17 1575  ax-ext 2216
This theorem depends on definitions:  df-bi 117  df-cleq 2227  df-fn 5360
This theorem is referenced by:  fneq2d  5452  fneq2i  5456  feq2  5497  foeq2  5592  f1o00  5656  eqfnfv2  5781  tfr0dm  6566  tfrlemisucaccv  6569  tfrlemi1  6576  tfrlemi14d  6577  tfrexlem  6578  tfr1onlemsucfn  6584  tfr1onlemsucaccv  6585  tfr1onlembxssdm  6587  tfr1onlembfn  6588  tfr1onlemaccex  6592  tfr1onlemres  6593  ixpeq1  6957  0fz1  10399
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