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Theorem fneq2 5419
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 2241 . . 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 5329 . 2 (𝐹 Fn 𝐴 ↔ (Fun 𝐹 ∧ dom 𝐹 = 𝐴))
4 df-fn 5329 . 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 1397  dom cdm 4725  Fun wfun 5320   Fn wfn 5321
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 1495  ax-gen 1497  ax-4 1558  ax-17 1574  ax-ext 2213
This theorem depends on definitions:  df-bi 117  df-cleq 2224  df-fn 5329
This theorem is referenced by:  fneq2d  5421  fneq2i  5425  feq2  5466  foeq2  5556  f1o00  5620  eqfnfv2  5745  tfr0dm  6487  tfrlemisucaccv  6490  tfrlemi1  6497  tfrlemi14d  6498  tfrexlem  6499  tfr1onlemsucfn  6505  tfr1onlemsucaccv  6506  tfr1onlembxssdm  6508  tfr1onlembfn  6509  tfr1onlemaccex  6513  tfr1onlemres  6514  ixpeq1  6877  0fz1  10279
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