Users' Mathboxes Mathbox for Zhi Wang < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  elfvne0 Structured version   Visualization version   GIF version

Theorem elfvne0 49339
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 4282 . 2 (𝐴 ∈ (𝐹𝐵) → (𝐹𝐵) ≠ ∅)
2 fveq1 6834 . . . 4 (𝐹 = ∅ → (𝐹𝐵) = (∅‘𝐵))
3 0fv 6876 . . . 4 (∅‘𝐵) = ∅
42, 3eqtrdi 2788 . . 3 (𝐹 = ∅ → (𝐹𝐵) = ∅)
54necon3i 2965 . 2 ((𝐹𝐵) ≠ ∅ → 𝐹 ≠ ∅)
61, 5syl 17 1 (𝐴 ∈ (𝐹𝐵) → 𝐹 ≠ ∅)
Colors of variables: wff setvar class
Syntax hints:  wi 4   = wceq 1542  wcel 2114  wne 2933  c0 4274  cfv 6493
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1912  ax-6 1969  ax-7 2010  ax-8 2116  ax-9 2124  ax-ext 2709  ax-nul 5242  ax-pr 5371
This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-3an 1089  df-tru 1545  df-fal 1555  df-ex 1782  df-sb 2069  df-mo 2540  df-eu 2570  df-clab 2716  df-cleq 2729  df-clel 2812  df-ne 2934  df-rab 3391  df-v 3432  df-dif 3893  df-un 3895  df-ss 3907  df-nul 4275  df-if 4468  df-sn 4569  df-pr 4571  df-op 4575  df-uni 4852  df-br 5087  df-dm 5635  df-iota 6449  df-fv 6501
This theorem is referenced by:  neircl  49395  sectrcl  49512  invrcl  49514  isorcl  49523  catcrcl  49885
  Copyright terms: Public domain W3C validator