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Mirrors > Home > ILE Home > Th. List > xp0 | GIF version |
Description: The cross product with the empty set is empty. Part of Theorem 3.13(ii) of [Monk1] p. 37. (Contributed by NM, 12-Apr-2004.) |
Ref | Expression |
---|---|
xp0 | ⊢ (𝐴 × ∅) = ∅ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0xp 4420 | . . 3 ⊢ (∅ × 𝐴) = ∅ | |
2 | 1 | cnveqi 4510 | . 2 ⊢ ◡(∅ × 𝐴) = ◡∅ |
3 | cnvxp 4742 | . 2 ⊢ ◡(∅ × 𝐴) = (𝐴 × ∅) | |
4 | cnv0 4727 | . 2 ⊢ ◡∅ = ∅ | |
5 | 2, 3, 4 | 3eqtr3i 2068 | 1 ⊢ (𝐴 × ∅) = ∅ |
Colors of variables: wff set class |
Syntax hints: = wceq 1243 ∅c0 3224 × cxp 4343 ◡ccnv 4344 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 99 ax-ia2 100 ax-ia3 101 ax-in1 544 ax-in2 545 ax-io 630 ax-5 1336 ax-7 1337 ax-gen 1338 ax-ie1 1382 ax-ie2 1383 ax-8 1395 ax-10 1396 ax-11 1397 ax-i12 1398 ax-bndl 1399 ax-4 1400 ax-14 1405 ax-17 1419 ax-i9 1423 ax-ial 1427 ax-i5r 1428 ax-ext 2022 ax-sep 3875 ax-pow 3927 ax-pr 3944 |
This theorem depends on definitions: df-bi 110 df-3an 887 df-tru 1246 df-fal 1249 df-nf 1350 df-sb 1646 df-eu 1903 df-mo 1904 df-clab 2027 df-cleq 2033 df-clel 2036 df-nfc 2167 df-ral 2311 df-rex 2312 df-v 2559 df-dif 2920 df-un 2922 df-in 2924 df-ss 2931 df-nul 3225 df-pw 3361 df-sn 3381 df-pr 3382 df-op 3384 df-br 3765 df-opab 3819 df-xp 4351 df-rel 4352 df-cnv 4353 |
This theorem is referenced by: xpeq0r 4746 xpdisj2 4748 |
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