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Mirrors > Home > ILE Home > Th. List > 0nelxp | Unicode version |
Description: The empty set is not a member of a cross product. (Contributed by NM, 2-May-1996.) (Revised by Mario Carneiro, 26-Apr-2015.) |
Ref | Expression |
---|---|
0nelxp |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | vex 2684 | . . . . . 6 | |
2 | vex 2684 | . . . . . 6 | |
3 | 1, 2 | opnzi 4152 | . . . . 5 |
4 | simpl 108 | . . . . . . 7 | |
5 | 4 | eqcomd 2143 | . . . . . 6 |
6 | 5 | necon3ai 2355 | . . . . 5 |
7 | 3, 6 | ax-mp 5 | . . . 4 |
8 | 7 | nex 1476 | . . 3 |
9 | 8 | nex 1476 | . 2 |
10 | elxp 4551 | . 2 | |
11 | 9, 10 | mtbir 660 | 1 |
Colors of variables: wff set class |
Syntax hints: wn 3 wa 103 wceq 1331 wex 1468 wcel 1480 wne 2306 c0 3358 cop 3525 cxp 4532 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-in1 603 ax-in2 604 ax-io 698 ax-5 1423 ax-7 1424 ax-gen 1425 ax-ie1 1469 ax-ie2 1470 ax-8 1482 ax-10 1483 ax-11 1484 ax-i12 1485 ax-bndl 1486 ax-4 1487 ax-14 1492 ax-17 1506 ax-i9 1510 ax-ial 1514 ax-i5r 1515 ax-ext 2119 ax-sep 4041 ax-pow 4093 ax-pr 4126 |
This theorem depends on definitions: df-bi 116 df-3an 964 df-tru 1334 df-fal 1337 df-nf 1437 df-sb 1736 df-clab 2124 df-cleq 2130 df-clel 2133 df-nfc 2268 df-ne 2307 df-v 2683 df-dif 3068 df-un 3070 df-in 3072 df-ss 3079 df-nul 3359 df-pw 3507 df-sn 3528 df-pr 3529 df-op 3531 df-opab 3985 df-xp 4540 |
This theorem is referenced by: 0nelrel 4580 dmsn0 5001 nfunv 5151 reldmtpos 6143 dmtpos 6146 0ncn 7632 structcnvcnv 11964 |
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