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| Mirrors > Home > MPE Home > Th. List > unxpdom | Structured version Visualization version GIF version | ||
| Description: Cartesian product dominates union for sets with cardinality greater than 1. Proposition 10.36 of [TakeutiZaring] p. 93. (Contributed by Mario Carneiro, 13-Jan-2013.) (Proof shortened by Mario Carneiro, 27-Apr-2015.) | 
| Ref | Expression | 
|---|---|
| unxpdom | ⊢ ((1o ≺ 𝐴 ∧ 1o ≺ 𝐵) → (𝐴 ∪ 𝐵) ≼ (𝐴 × 𝐵)) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | relsdom 8992 | . . . 4 ⊢ Rel ≺ | |
| 2 | 1 | brrelex2i 5742 | . . 3 ⊢ (1o ≺ 𝐴 → 𝐴 ∈ V) | 
| 3 | 1 | brrelex2i 5742 | . . 3 ⊢ (1o ≺ 𝐵 → 𝐵 ∈ V) | 
| 4 | 2, 3 | anim12i 613 | . 2 ⊢ ((1o ≺ 𝐴 ∧ 1o ≺ 𝐵) → (𝐴 ∈ V ∧ 𝐵 ∈ V)) | 
| 5 | breq2 5147 | . . . . 5 ⊢ (𝑥 = 𝐴 → (1o ≺ 𝑥 ↔ 1o ≺ 𝐴)) | |
| 6 | 5 | anbi1d 631 | . . . 4 ⊢ (𝑥 = 𝐴 → ((1o ≺ 𝑥 ∧ 1o ≺ 𝑦) ↔ (1o ≺ 𝐴 ∧ 1o ≺ 𝑦))) | 
| 7 | uneq1 4161 | . . . . 5 ⊢ (𝑥 = 𝐴 → (𝑥 ∪ 𝑦) = (𝐴 ∪ 𝑦)) | |
| 8 | xpeq1 5699 | . . . . 5 ⊢ (𝑥 = 𝐴 → (𝑥 × 𝑦) = (𝐴 × 𝑦)) | |
| 9 | 7, 8 | breq12d 5156 | . . . 4 ⊢ (𝑥 = 𝐴 → ((𝑥 ∪ 𝑦) ≼ (𝑥 × 𝑦) ↔ (𝐴 ∪ 𝑦) ≼ (𝐴 × 𝑦))) | 
| 10 | 6, 9 | imbi12d 344 | . . 3 ⊢ (𝑥 = 𝐴 → (((1o ≺ 𝑥 ∧ 1o ≺ 𝑦) → (𝑥 ∪ 𝑦) ≼ (𝑥 × 𝑦)) ↔ ((1o ≺ 𝐴 ∧ 1o ≺ 𝑦) → (𝐴 ∪ 𝑦) ≼ (𝐴 × 𝑦)))) | 
| 11 | breq2 5147 | . . . . 5 ⊢ (𝑦 = 𝐵 → (1o ≺ 𝑦 ↔ 1o ≺ 𝐵)) | |
| 12 | 11 | anbi2d 630 | . . . 4 ⊢ (𝑦 = 𝐵 → ((1o ≺ 𝐴 ∧ 1o ≺ 𝑦) ↔ (1o ≺ 𝐴 ∧ 1o ≺ 𝐵))) | 
| 13 | uneq2 4162 | . . . . 5 ⊢ (𝑦 = 𝐵 → (𝐴 ∪ 𝑦) = (𝐴 ∪ 𝐵)) | |
| 14 | xpeq2 5706 | . . . . 5 ⊢ (𝑦 = 𝐵 → (𝐴 × 𝑦) = (𝐴 × 𝐵)) | |
| 15 | 13, 14 | breq12d 5156 | . . . 4 ⊢ (𝑦 = 𝐵 → ((𝐴 ∪ 𝑦) ≼ (𝐴 × 𝑦) ↔ (𝐴 ∪ 𝐵) ≼ (𝐴 × 𝐵))) | 
| 16 | 12, 15 | imbi12d 344 | . . 3 ⊢ (𝑦 = 𝐵 → (((1o ≺ 𝐴 ∧ 1o ≺ 𝑦) → (𝐴 ∪ 𝑦) ≼ (𝐴 × 𝑦)) ↔ ((1o ≺ 𝐴 ∧ 1o ≺ 𝐵) → (𝐴 ∪ 𝐵) ≼ (𝐴 × 𝐵)))) | 
| 17 | eqid 2737 | . . . 4 ⊢ (𝑧 ∈ (𝑥 ∪ 𝑦) ↦ if(𝑧 ∈ 𝑥, 〈𝑧, if(𝑧 = 𝑣, 𝑤, 𝑡)〉, 〈if(𝑧 = 𝑤, 𝑢, 𝑣), 𝑧〉)) = (𝑧 ∈ (𝑥 ∪ 𝑦) ↦ if(𝑧 ∈ 𝑥, 〈𝑧, if(𝑧 = 𝑣, 𝑤, 𝑡)〉, 〈if(𝑧 = 𝑤, 𝑢, 𝑣), 𝑧〉)) | |
| 18 | eqid 2737 | . . . 4 ⊢ if(𝑧 ∈ 𝑥, 〈𝑧, if(𝑧 = 𝑣, 𝑤, 𝑡)〉, 〈if(𝑧 = 𝑤, 𝑢, 𝑣), 𝑧〉) = if(𝑧 ∈ 𝑥, 〈𝑧, if(𝑧 = 𝑣, 𝑤, 𝑡)〉, 〈if(𝑧 = 𝑤, 𝑢, 𝑣), 𝑧〉) | |
| 19 | 17, 18 | unxpdomlem3 9288 | . . 3 ⊢ ((1o ≺ 𝑥 ∧ 1o ≺ 𝑦) → (𝑥 ∪ 𝑦) ≼ (𝑥 × 𝑦)) | 
| 20 | 10, 16, 19 | vtocl2g 3574 | . 2 ⊢ ((𝐴 ∈ V ∧ 𝐵 ∈ V) → ((1o ≺ 𝐴 ∧ 1o ≺ 𝐵) → (𝐴 ∪ 𝐵) ≼ (𝐴 × 𝐵))) | 
| 21 | 4, 20 | mpcom 38 | 1 ⊢ ((1o ≺ 𝐴 ∧ 1o ≺ 𝐵) → (𝐴 ∪ 𝐵) ≼ (𝐴 × 𝐵)) | 
| Colors of variables: wff setvar class | 
| Syntax hints: → wi 4 ∧ wa 395 = wceq 1540 ∈ wcel 2108 Vcvv 3480 ∪ cun 3949 ifcif 4525 〈cop 4632 class class class wbr 5143 ↦ cmpt 5225 × cxp 5683 1oc1o 8499 ≼ cdom 8983 ≺ csdm 8984 | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1910 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-10 2141 ax-11 2157 ax-12 2177 ax-ext 2708 ax-sep 5296 ax-nul 5306 ax-pow 5365 ax-pr 5432 ax-un 7755 | 
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-3an 1089 df-tru 1543 df-fal 1553 df-ex 1780 df-nf 1784 df-sb 2065 df-mo 2540 df-eu 2569 df-clab 2715 df-cleq 2729 df-clel 2816 df-nfc 2892 df-ne 2941 df-ral 3062 df-rex 3071 df-rab 3437 df-v 3482 df-dif 3954 df-un 3956 df-in 3958 df-ss 3968 df-nul 4334 df-if 4526 df-pw 4602 df-sn 4627 df-pr 4629 df-op 4633 df-uni 4908 df-br 5144 df-opab 5206 df-mpt 5226 df-id 5578 df-xp 5691 df-rel 5692 df-cnv 5693 df-co 5694 df-dm 5695 df-rn 5696 df-res 5697 df-ima 5698 df-suc 6390 df-iota 6514 df-fun 6563 df-fn 6564 df-f 6565 df-f1 6566 df-fo 6567 df-f1o 6568 df-fv 6569 df-1o 8506 df-2o 8507 df-en 8986 df-dom 8987 df-sdom 8988 | 
| This theorem is referenced by: unxpdom2 9290 sucxpdom 9291 djuxpdom 10226 | 
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