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Theorem elfvne0 49627
Description: If a function value has a member, then the function is not an empty set (An artifact of our function value definition.) (Contributed by Zhi Wang, 16-Sep-2024.)
Assertion
Ref Expression
elfvne0 (𝐴 ∈ (𝐹𝐵) → 𝐹 ≠ ∅)

Proof of Theorem elfvne0
StepHypRef Expression
1 ne0i 4294 . 2 (𝐴 ∈ (𝐹𝐵) → (𝐹𝐵) ≠ ∅)
2 fveq1 6880 . . . 4 (𝐹 = ∅ → (𝐹𝐵) = (∅‘𝐵))
3 0fv 6922 . . . 4 (∅‘𝐵) = ∅
42, 3eqtrdi 2814 . . 3 (𝐹 = ∅ → (𝐹𝐵) = ∅)
54necon3i 2990 . 2 ((𝐹𝐵) ≠ ∅ → 𝐹 ≠ ∅)
61, 5syl 18 1 (𝐴 ∈ (𝐹𝐵) → 𝐹 ≠ ∅)
Colors of variables: wff setvar class
Syntax hints:  wi 4   = wceq 1570  wcel 2143  wne 2958  c0 4286  cfv 6536
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1825  ax-4 1839  ax-5 1940  ax-6 1997  ax-7 2038  ax-8 2145  ax-9 2153  ax-ext 2735  ax-nul 5269  ax-pr 5404
This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1810  df-sb 2097  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2838  df-ne 2959  df-rab 3417  df-v 3457  df-dif 3908  df-un 3910  df-ss 3922  df-nul 4287  df-if 4488  df-sn 4590  df-pr 4592  df-op 4596  df-uni 4873  df-br 5110  df-dm 5671  df-iota 6492  df-fv 6544
This theorem is referenced by:  neircl  49683  sectrcl  49800  invrcl  49802  isorcl  49811  catcrcl  50173
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