| 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 4295 | . 2 ⊢ (𝑋 ∈ dom 𝐹 → dom 𝐹 ≠ ∅) | |
| 2 | dmeq 5895 | . . . 4 ⊢ (𝐹 = ∅ → dom 𝐹 = dom ∅) | |
| 3 | dm0 5912 | . . . 4 ⊢ dom ∅ = ∅ | |
| 4 | 2, 3 | eqtrdi 2814 | . . 3 ⊢ (𝐹 = ∅ → dom 𝐹 = ∅) |
| 5 | 4 | necon3i 2990 | . 2 ⊢ (dom 𝐹 ≠ ∅ → 𝐹 ≠ ∅) |
| 6 | 1, 5 | syl 18 | 1 ⊢ (𝑋 ∈ dom 𝐹 → 𝐹 ≠ ∅) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 = wceq 1570 ∈ wcel 2143 ≠ wne 2958 ∅c0 4287 dom cdm 5663 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1825 ax-4 1839 ax-5 1940 ax-6 1997 ax-7 2038 ax-8 2145 ax-9 2153 ax-ext 2735 |
| This theorem depends on definitions: df-bi 210 df-an 401 df-or 861 df-3an 1105 df-tru 1573 df-fal 1583 df-ex 1810 df-sb 2097 df-clab 2742 df-cleq 2755 df-clel 2838 df-ne 2959 df-rab 3417 df-v 3457 df-dif 3909 df-un 3911 df-ss 3923 df-nul 4288 df-if 4489 df-sn 4591 df-pr 4593 df-op 4597 df-br 5111 df-dm 5673 |
| This theorem is referenced by: cycpmrn 33444 |
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