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Mirrors > Home > MPE Home > Th. List > eliman0 | Structured version Visualization version GIF version |
Description: A non-nul function value is an element of the image of the function. (Contributed by Thierry Arnoux, 25-Jun-2019.) |
Ref | Expression |
---|---|
eliman0 | ⊢ ((𝐴 ∈ 𝐵 ∧ ¬ (𝐹‘𝐴) = ∅) → (𝐹‘𝐴) ∈ (𝐹 “ 𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fvbr0 6125 | . . . . 5 ⊢ (𝐴𝐹(𝐹‘𝐴) ∨ (𝐹‘𝐴) = ∅) | |
2 | orcom 401 | . . . . 5 ⊢ ((𝐴𝐹(𝐹‘𝐴) ∨ (𝐹‘𝐴) = ∅) ↔ ((𝐹‘𝐴) = ∅ ∨ 𝐴𝐹(𝐹‘𝐴))) | |
3 | 1, 2 | mpbi 219 | . . . 4 ⊢ ((𝐹‘𝐴) = ∅ ∨ 𝐴𝐹(𝐹‘𝐴)) |
4 | 3 | ori 389 | . . 3 ⊢ (¬ (𝐹‘𝐴) = ∅ → 𝐴𝐹(𝐹‘𝐴)) |
5 | breq1 4586 | . . . 4 ⊢ (𝑥 = 𝐴 → (𝑥𝐹(𝐹‘𝐴) ↔ 𝐴𝐹(𝐹‘𝐴))) | |
6 | 5 | rspcev 3282 | . . 3 ⊢ ((𝐴 ∈ 𝐵 ∧ 𝐴𝐹(𝐹‘𝐴)) → ∃𝑥 ∈ 𝐵 𝑥𝐹(𝐹‘𝐴)) |
7 | 4, 6 | sylan2 490 | . 2 ⊢ ((𝐴 ∈ 𝐵 ∧ ¬ (𝐹‘𝐴) = ∅) → ∃𝑥 ∈ 𝐵 𝑥𝐹(𝐹‘𝐴)) |
8 | fvex 6113 | . . 3 ⊢ (𝐹‘𝐴) ∈ V | |
9 | 8 | elima 5390 | . 2 ⊢ ((𝐹‘𝐴) ∈ (𝐹 “ 𝐵) ↔ ∃𝑥 ∈ 𝐵 𝑥𝐹(𝐹‘𝐴)) |
10 | 7, 9 | sylibr 223 | 1 ⊢ ((𝐴 ∈ 𝐵 ∧ ¬ (𝐹‘𝐴) = ∅) → (𝐹‘𝐴) ∈ (𝐹 “ 𝐵)) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∨ wo 382 ∧ wa 383 = wceq 1475 ∈ wcel 1977 ∃wrex 2897 ∅c0 3874 class class class wbr 4583 “ cima 5041 ‘cfv 5804 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-sep 4709 ax-nul 4717 ax-pr 4833 |
This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-eu 2462 df-mo 2463 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ne 2782 df-ral 2901 df-rex 2902 df-rab 2905 df-v 3175 df-sbc 3403 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-nul 3875 df-if 4037 df-sn 4126 df-pr 4128 df-op 4132 df-uni 4373 df-br 4584 df-opab 4644 df-xp 5044 df-cnv 5046 df-dm 5048 df-rn 5049 df-res 5050 df-ima 5051 df-iota 5768 df-fv 5812 |
This theorem is referenced by: ovima0 6711 setrec2fun 42238 |
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