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Mirrors > Home > MPE Home > Th. List > eliman0 | Structured version Visualization version GIF version |
Description: A nonempty 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 6936 | . . . . 5 ⊢ (𝐴𝐹(𝐹‘𝐴) ∨ (𝐹‘𝐴) = ∅) | |
2 | orcom 870 | . . . . 5 ⊢ ((𝐴𝐹(𝐹‘𝐴) ∨ (𝐹‘𝐴) = ∅) ↔ ((𝐹‘𝐴) = ∅ ∨ 𝐴𝐹(𝐹‘𝐴))) | |
3 | 1, 2 | mpbi 230 | . . . 4 ⊢ ((𝐹‘𝐴) = ∅ ∨ 𝐴𝐹(𝐹‘𝐴)) |
4 | 3 | ori 861 | . . 3 ⊢ (¬ (𝐹‘𝐴) = ∅ → 𝐴𝐹(𝐹‘𝐴)) |
5 | breq1 5151 | . . . 4 ⊢ (𝑥 = 𝐴 → (𝑥𝐹(𝐹‘𝐴) ↔ 𝐴𝐹(𝐹‘𝐴))) | |
6 | 5 | rspcev 3622 | . . 3 ⊢ ((𝐴 ∈ 𝐵 ∧ 𝐴𝐹(𝐹‘𝐴)) → ∃𝑥 ∈ 𝐵 𝑥𝐹(𝐹‘𝐴)) |
7 | 4, 6 | sylan2 593 | . 2 ⊢ ((𝐴 ∈ 𝐵 ∧ ¬ (𝐹‘𝐴) = ∅) → ∃𝑥 ∈ 𝐵 𝑥𝐹(𝐹‘𝐴)) |
8 | fvex 6920 | . . 3 ⊢ (𝐹‘𝐴) ∈ V | |
9 | 8 | elima 6085 | . 2 ⊢ ((𝐹‘𝐴) ∈ (𝐹 “ 𝐵) ↔ ∃𝑥 ∈ 𝐵 𝑥𝐹(𝐹‘𝐴)) |
10 | 7, 9 | sylibr 234 | 1 ⊢ ((𝐴 ∈ 𝐵 ∧ ¬ (𝐹‘𝐴) = ∅) → (𝐹‘𝐴) ∈ (𝐹 “ 𝐵)) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 395 ∨ wo 847 = wceq 1537 ∈ wcel 2106 ∃wrex 3068 ∅c0 4339 class class class wbr 5148 “ cima 5692 ‘cfv 6563 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1908 ax-6 1965 ax-7 2005 ax-8 2108 ax-9 2116 ax-10 2139 ax-11 2155 ax-12 2175 ax-ext 2706 ax-sep 5302 ax-nul 5312 ax-pr 5438 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3an 1088 df-tru 1540 df-fal 1550 df-ex 1777 df-nf 1781 df-sb 2063 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2727 df-clel 2814 df-ne 2939 df-ral 3060 df-rex 3069 df-rab 3434 df-v 3480 df-dif 3966 df-un 3968 df-in 3970 df-ss 3980 df-nul 4340 df-if 4532 df-sn 4632 df-pr 4634 df-op 4638 df-uni 4913 df-br 5149 df-opab 5211 df-xp 5695 df-cnv 5697 df-dm 5699 df-rn 5700 df-res 5701 df-ima 5702 df-iota 6516 df-fv 6571 |
This theorem is referenced by: ovima0 7612 setrec2fun 48923 |
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