| Mathbox for Thierry Arnoux |
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| Mirrors > Home > MPE Home > Th. List > Mathboxes > eldmne0 | Structured version Visualization version GIF version | ||
| Description: A function of nonempty domain is not empty. (Contributed by Thierry Arnoux, 20-Nov-2023.) |
| Ref | Expression |
|---|---|
| eldmne0 | ⊢ (𝑋 ∈ dom 𝐹 → 𝐹 ≠ ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ne0i 4292 | . 2 ⊢ (𝑋 ∈ dom 𝐹 → dom 𝐹 ≠ ∅) | |
| 2 | dmeq 5850 | . . . 4 ⊢ (𝐹 = ∅ → dom 𝐹 = dom ∅) | |
| 3 | dm0 5867 | . . . 4 ⊢ dom ∅ = ∅ | |
| 4 | 2, 3 | eqtrdi 2784 | . . 3 ⊢ (𝐹 = ∅ → dom 𝐹 = ∅) |
| 5 | 4 | necon3i 2962 | . 2 ⊢ (dom 𝐹 ≠ ∅ → 𝐹 ≠ ∅) |
| 6 | 1, 5 | syl 17 | 1 ⊢ (𝑋 ∈ dom 𝐹 → 𝐹 ≠ ∅) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 = wceq 1541 ∈ wcel 2113 ≠ wne 2930 ∅c0 4284 dom cdm 5621 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1968 ax-7 2009 ax-8 2115 ax-9 2123 ax-ext 2705 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3an 1088 df-tru 1544 df-fal 1554 df-ex 1781 df-sb 2068 df-clab 2712 df-cleq 2725 df-clel 2808 df-ne 2931 df-rab 3398 df-v 3440 df-dif 3902 df-un 3904 df-ss 3916 df-nul 4285 df-if 4477 df-sn 4578 df-pr 4580 df-op 4584 df-br 5096 df-dm 5631 |
| This theorem is referenced by: cycpmrn 33123 |
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