| 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 4276 | . 2 ⊢ (𝑋 ∈ dom 𝐹 → dom 𝐹 ≠ ∅) | |
| 2 | dmeq 5852 | . . . 4 ⊢ (𝐹 = ∅ → dom 𝐹 = dom ∅) | |
| 3 | dm0 5869 | . . . 4 ⊢ dom ∅ = ∅ | |
| 4 | 2, 3 | eqtrdi 2791 | . . 3 ⊢ (𝐹 = ∅ → dom 𝐹 = ∅) |
| 5 | 4 | necon3i 2967 | . 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 1547 ∈ wcel 2119 ≠ wne 2935 ∅c0 4268 dom cdm 5625 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1802 ax-4 1816 ax-5 1917 ax-6 1974 ax-7 2015 ax-8 2121 ax-9 2129 ax-ext 2712 |
| This theorem depends on definitions: df-bi 208 df-an 397 df-or 854 df-3an 1094 df-tru 1550 df-fal 1560 df-ex 1787 df-sb 2074 df-clab 2719 df-cleq 2732 df-clel 2815 df-ne 2936 df-rab 3393 df-v 3434 df-dif 3893 df-un 3895 df-ss 3907 df-nul 4269 df-if 4462 df-sn 4563 df-pr 4565 df-op 4569 df-br 5080 df-dm 5635 |
| This theorem is referenced by: cycpmrn 33231 |
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