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| Mirrors > Home > ILE Home > Th. List > xp01disjl | GIF version | ||
| Description: Cartesian products with the singletons of ordinals 0 and 1 are disjoint. (Contributed by Jim Kingdon, 11-Jul-2023.) | 
| Ref | Expression | 
|---|---|
| xp01disjl | ⊢ (({∅} × 𝐴) ∩ ({1o} × 𝐶)) = ∅ | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 1n0 6490 | . . 3 ⊢ 1o ≠ ∅ | |
| 2 | 1 | necomi 2452 | . 2 ⊢ ∅ ≠ 1o | 
| 3 | disjsn2 3685 | . 2 ⊢ (∅ ≠ 1o → ({∅} ∩ {1o}) = ∅) | |
| 4 | xpdisj1 5094 | . 2 ⊢ (({∅} ∩ {1o}) = ∅ → (({∅} × 𝐴) ∩ ({1o} × 𝐶)) = ∅) | |
| 5 | 2, 3, 4 | mp2b 8 | 1 ⊢ (({∅} × 𝐴) ∩ ({1o} × 𝐶)) = ∅ | 
| Colors of variables: wff set class | 
| Syntax hints: = wceq 1364 ≠ wne 2367 ∩ cin 3156 ∅c0 3450 {csn 3622 × cxp 4661 1oc1o 6467 | 
| 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-in1 615 ax-in2 616 ax-io 710 ax-5 1461 ax-7 1462 ax-gen 1463 ax-ie1 1507 ax-ie2 1508 ax-8 1518 ax-10 1519 ax-11 1520 ax-i12 1521 ax-bndl 1523 ax-4 1524 ax-17 1540 ax-i9 1544 ax-ial 1548 ax-i5r 1549 ax-14 2170 ax-ext 2178 ax-sep 4151 ax-nul 4159 ax-pow 4207 ax-pr 4242 | 
| This theorem depends on definitions: df-bi 117 df-3an 982 df-tru 1367 df-fal 1370 df-nf 1475 df-sb 1777 df-clab 2183 df-cleq 2189 df-clel 2192 df-nfc 2328 df-ne 2368 df-ral 2480 df-rex 2481 df-v 2765 df-dif 3159 df-un 3161 df-in 3163 df-ss 3170 df-nul 3451 df-pw 3607 df-sn 3628 df-pr 3629 df-op 3631 df-opab 4095 df-suc 4406 df-xp 4669 df-rel 4670 df-1o 6474 | 
| This theorem is referenced by: djucomen 7283 djuassen 7284 xpdjuen 7285 | 
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