Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > 0xp | Structured version Visualization version GIF version |
Description: The Cartesian product with the empty set is empty. Part of Theorem 3.13(ii) of [Monk1] p. 37. (Contributed by NM, 4-Jul-1994.) |
Ref | Expression |
---|---|
0xp | ⊢ (∅ × 𝐴) = ∅ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elxp 5055 | . . 3 ⊢ (𝑧 ∈ (∅ × 𝐴) ↔ ∃𝑥∃𝑦(𝑧 = 〈𝑥, 𝑦〉 ∧ (𝑥 ∈ ∅ ∧ 𝑦 ∈ 𝐴))) | |
2 | noel 3878 | . . . . . . 7 ⊢ ¬ 𝑥 ∈ ∅ | |
3 | simprl 790 | . . . . . . 7 ⊢ ((𝑧 = 〈𝑥, 𝑦〉 ∧ (𝑥 ∈ ∅ ∧ 𝑦 ∈ 𝐴)) → 𝑥 ∈ ∅) | |
4 | 2, 3 | mto 187 | . . . . . 6 ⊢ ¬ (𝑧 = 〈𝑥, 𝑦〉 ∧ (𝑥 ∈ ∅ ∧ 𝑦 ∈ 𝐴)) |
5 | 4 | nex 1722 | . . . . 5 ⊢ ¬ ∃𝑦(𝑧 = 〈𝑥, 𝑦〉 ∧ (𝑥 ∈ ∅ ∧ 𝑦 ∈ 𝐴)) |
6 | 5 | nex 1722 | . . . 4 ⊢ ¬ ∃𝑥∃𝑦(𝑧 = 〈𝑥, 𝑦〉 ∧ (𝑥 ∈ ∅ ∧ 𝑦 ∈ 𝐴)) |
7 | noel 3878 | . . . 4 ⊢ ¬ 𝑧 ∈ ∅ | |
8 | 6, 7 | 2false 364 | . . 3 ⊢ (∃𝑥∃𝑦(𝑧 = 〈𝑥, 𝑦〉 ∧ (𝑥 ∈ ∅ ∧ 𝑦 ∈ 𝐴)) ↔ 𝑧 ∈ ∅) |
9 | 1, 8 | bitri 263 | . 2 ⊢ (𝑧 ∈ (∅ × 𝐴) ↔ 𝑧 ∈ ∅) |
10 | 9 | eqriv 2607 | 1 ⊢ (∅ × 𝐴) = ∅ |
Colors of variables: wff setvar class |
Syntax hints: ∧ wa 383 = wceq 1475 ∃wex 1695 ∈ wcel 1977 ∅c0 3874 〈cop 4131 × cxp 5036 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-sep 4709 ax-nul 4717 ax-pr 4833 |
This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-v 3175 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-nul 3875 df-if 4037 df-sn 4126 df-pr 4128 df-op 4132 df-opab 4644 df-xp 5044 |
This theorem is referenced by: dmxpid 5266 csbres 5320 res0 5321 xp0 5471 xpnz 5472 xpdisj1 5474 difxp2 5479 xpcan2 5490 xpima 5495 unixp 5585 unixpid 5587 xpcoid 5593 fodomr 7996 xpfi 8116 cdaassen 8887 iundom2g 9241 alephadd 9278 hashxplem 13080 dmtrclfv 13607 ramcl 15571 0subcat 16321 mat0dimbas0 20091 mavmul0g 20178 txindislem 21246 txhaus 21260 tmdgsum 21709 ust0 21833 sibf0 29723 mexval2 30654 poimirlem5 32584 poimirlem10 32589 poimirlem22 32601 poimirlem23 32602 poimirlem26 32605 poimirlem28 32607 0mbf 32625 0heALT 37097 |
Copyright terms: Public domain | W3C validator |