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| Mirrors > Home > ILE Home > Th. List > prmg | GIF version | ||
| Description: A pair containing a set is inhabited. (Contributed by Jim Kingdon, 21-Sep-2018.) |
| Ref | Expression |
|---|---|
| prmg | ⊢ (𝐴 ∈ 𝑉 → ∃𝑥 𝑥 ∈ {𝐴, 𝐵}) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | snmg 3751 | . 2 ⊢ (𝐴 ∈ 𝑉 → ∃𝑥 𝑥 ∈ {𝐴}) | |
| 2 | orc 714 | . . . 4 ⊢ (𝑥 = 𝐴 → (𝑥 = 𝐴 ∨ 𝑥 = 𝐵)) | |
| 3 | velsn 3650 | . . . 4 ⊢ (𝑥 ∈ {𝐴} ↔ 𝑥 = 𝐴) | |
| 4 | vex 2775 | . . . . 5 ⊢ 𝑥 ∈ V | |
| 5 | 4 | elpr 3654 | . . . 4 ⊢ (𝑥 ∈ {𝐴, 𝐵} ↔ (𝑥 = 𝐴 ∨ 𝑥 = 𝐵)) |
| 6 | 2, 3, 5 | 3imtr4i 201 | . . 3 ⊢ (𝑥 ∈ {𝐴} → 𝑥 ∈ {𝐴, 𝐵}) |
| 7 | 6 | eximi 1623 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝐴} → ∃𝑥 𝑥 ∈ {𝐴, 𝐵}) |
| 8 | 1, 7 | syl 14 | 1 ⊢ (𝐴 ∈ 𝑉 → ∃𝑥 𝑥 ∈ {𝐴, 𝐵}) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ∨ wo 710 = wceq 1373 ∃wex 1515 ∈ wcel 2176 {csn 3633 {cpr 3634 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-io 711 ax-5 1470 ax-7 1471 ax-gen 1472 ax-ie1 1516 ax-ie2 1517 ax-8 1527 ax-10 1528 ax-11 1529 ax-i12 1530 ax-bndl 1532 ax-4 1533 ax-17 1549 ax-i9 1553 ax-ial 1557 ax-i5r 1558 ax-ext 2187 |
| This theorem depends on definitions: df-bi 117 df-tru 1376 df-nf 1484 df-sb 1786 df-clab 2192 df-cleq 2198 df-clel 2201 df-nfc 2337 df-v 2774 df-un 3170 df-sn 3639 df-pr 3640 |
| This theorem is referenced by: prm 3756 opm 4278 onintexmid 4621 subrngin 13975 subrgin 14006 lssincl 14147 |
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