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| Mirrors > Home > MPE Home > Th. List > djudom1 | Structured version Visualization version GIF version | ||
| Description: Ordering law for cardinal addition. Exercise 4.56(f) of [Mendelson] p. 258. (Contributed by NM, 28-Sep-2004.) (Revised by Mario Carneiro, 29-Apr-2015.) (Revised by Jim Kingdon, 1-Sep-2023.) |
| Ref | Expression |
|---|---|
| djudom1 | ⊢ ((𝐴 ≼ 𝐵 ∧ 𝐶 ∈ 𝑉) → (𝐴 ⊔ 𝐶) ≼ (𝐵 ⊔ 𝐶)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | snex 5436 | . . . 4 ⊢ {∅} ∈ V | |
| 2 | 1 | xpdom2 9107 | . . 3 ⊢ (𝐴 ≼ 𝐵 → ({∅} × 𝐴) ≼ ({∅} × 𝐵)) |
| 3 | snex 5436 | . . . . 5 ⊢ {1o} ∈ V | |
| 4 | xpexg 7770 | . . . . 5 ⊢ (({1o} ∈ V ∧ 𝐶 ∈ 𝑉) → ({1o} × 𝐶) ∈ V) | |
| 5 | 3, 4 | mpan 690 | . . . 4 ⊢ (𝐶 ∈ 𝑉 → ({1o} × 𝐶) ∈ V) |
| 6 | domrefg 9027 | . . . 4 ⊢ (({1o} × 𝐶) ∈ V → ({1o} × 𝐶) ≼ ({1o} × 𝐶)) | |
| 7 | 5, 6 | syl 17 | . . 3 ⊢ (𝐶 ∈ 𝑉 → ({1o} × 𝐶) ≼ ({1o} × 𝐶)) |
| 8 | xp01disjl 8530 | . . . 4 ⊢ (({∅} × 𝐵) ∩ ({1o} × 𝐶)) = ∅ | |
| 9 | undom 9099 | . . . 4 ⊢ (((({∅} × 𝐴) ≼ ({∅} × 𝐵) ∧ ({1o} × 𝐶) ≼ ({1o} × 𝐶)) ∧ (({∅} × 𝐵) ∩ ({1o} × 𝐶)) = ∅) → (({∅} × 𝐴) ∪ ({1o} × 𝐶)) ≼ (({∅} × 𝐵) ∪ ({1o} × 𝐶))) | |
| 10 | 8, 9 | mpan2 691 | . . 3 ⊢ ((({∅} × 𝐴) ≼ ({∅} × 𝐵) ∧ ({1o} × 𝐶) ≼ ({1o} × 𝐶)) → (({∅} × 𝐴) ∪ ({1o} × 𝐶)) ≼ (({∅} × 𝐵) ∪ ({1o} × 𝐶))) |
| 11 | 2, 7, 10 | syl2an 596 | . 2 ⊢ ((𝐴 ≼ 𝐵 ∧ 𝐶 ∈ 𝑉) → (({∅} × 𝐴) ∪ ({1o} × 𝐶)) ≼ (({∅} × 𝐵) ∪ ({1o} × 𝐶))) |
| 12 | df-dju 9941 | . 2 ⊢ (𝐴 ⊔ 𝐶) = (({∅} × 𝐴) ∪ ({1o} × 𝐶)) | |
| 13 | df-dju 9941 | . 2 ⊢ (𝐵 ⊔ 𝐶) = (({∅} × 𝐵) ∪ ({1o} × 𝐶)) | |
| 14 | 11, 12, 13 | 3brtr4g 5177 | 1 ⊢ ((𝐴 ≼ 𝐵 ∧ 𝐶 ∈ 𝑉) → (𝐴 ⊔ 𝐶) ≼ (𝐵 ⊔ 𝐶)) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 ∧ wa 395 = wceq 1540 ∈ wcel 2108 Vcvv 3480 ∪ cun 3949 ∩ cin 3950 ∅c0 4333 {csn 4626 class class class wbr 5143 × cxp 5683 1oc1o 8499 ≼ cdom 8983 ⊔ cdju 9938 |
| 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-sbc 3789 df-csb 3900 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-en 8986 df-dom 8987 df-dju 9941 |
| This theorem is referenced by: djudom2 10224 djulepw 10233 unctb 10244 infdif 10248 gchdjuidm 10708 gchpwdom 10710 gchhar 10719 pr2dom 43540 tr3dom 43541 |
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