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Theorem elfvne0 48853
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 6825 . . . 4 (𝐹 = ∅ → (𝐹𝐵) = (∅‘𝐵))
3 0fv 6868 . . . 4 (∅‘𝐵) = ∅
42, 3eqtrdi 2780 . . 3 (𝐹 = ∅ → (𝐹𝐵) = ∅)
54necon3i 2957 . 2 ((𝐹𝐵) ≠ ∅ → 𝐹 ≠ ∅)
61, 5syl 17 1 (𝐴 ∈ (𝐹𝐵) → 𝐹 ≠ ∅)
Colors of variables: wff setvar class
Syntax hints:  wi 4   = wceq 1540  wcel 2109  wne 2925  c0 4286  cfv 6486
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-10 2142  ax-11 2158  ax-12 2178  ax-ext 2701  ax-nul 5248  ax-pr 5374
This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2066  df-mo 2533  df-eu 2562  df-clab 2708  df-cleq 2721  df-clel 2803  df-ne 2926  df-ral 3045  df-rex 3054  df-rab 3397  df-v 3440  df-dif 3908  df-un 3910  df-ss 3922  df-nul 4287  df-if 4479  df-sn 4580  df-pr 4582  df-op 4586  df-uni 4862  df-br 5096  df-dm 5633  df-iota 6442  df-fv 6494
This theorem is referenced by:  neircl  48909  sectrcl  49027  invrcl  49029  isorcl  49038  catcrcl  49400
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