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Mirrors > Home > ILE Home > Th. List > djucomen | GIF version |
Description: Commutative law for cardinal addition. Exercise 4.56(c) of [Mendelson] p. 258. (Contributed by NM, 24-Sep-2004.) (Revised by Mario Carneiro, 29-Apr-2015.) |
Ref | Expression |
---|---|
djucomen | ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ⊔ 𝐵) ≈ (𝐵 ⊔ 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 1oex 6321 | . . . 4 ⊢ 1o ∈ V | |
2 | xpsnen2g 6723 | . . . 4 ⊢ ((1o ∈ V ∧ 𝐴 ∈ 𝑉) → ({1o} × 𝐴) ≈ 𝐴) | |
3 | 1, 2 | mpan 420 | . . 3 ⊢ (𝐴 ∈ 𝑉 → ({1o} × 𝐴) ≈ 𝐴) |
4 | 0ex 4055 | . . . 4 ⊢ ∅ ∈ V | |
5 | xpsnen2g 6723 | . . . 4 ⊢ ((∅ ∈ V ∧ 𝐵 ∈ 𝑊) → ({∅} × 𝐵) ≈ 𝐵) | |
6 | 4, 5 | mpan 420 | . . 3 ⊢ (𝐵 ∈ 𝑊 → ({∅} × 𝐵) ≈ 𝐵) |
7 | ensym 6675 | . . . 4 ⊢ (({1o} × 𝐴) ≈ 𝐴 → 𝐴 ≈ ({1o} × 𝐴)) | |
8 | ensym 6675 | . . . 4 ⊢ (({∅} × 𝐵) ≈ 𝐵 → 𝐵 ≈ ({∅} × 𝐵)) | |
9 | incom 3268 | . . . . . 6 ⊢ (({1o} × 𝐴) ∩ ({∅} × 𝐵)) = (({∅} × 𝐵) ∩ ({1o} × 𝐴)) | |
10 | xp01disjl 6331 | . . . . . 6 ⊢ (({∅} × 𝐵) ∩ ({1o} × 𝐴)) = ∅ | |
11 | 9, 10 | eqtri 2160 | . . . . 5 ⊢ (({1o} × 𝐴) ∩ ({∅} × 𝐵)) = ∅ |
12 | djuenun 7068 | . . . . 5 ⊢ ((𝐴 ≈ ({1o} × 𝐴) ∧ 𝐵 ≈ ({∅} × 𝐵) ∧ (({1o} × 𝐴) ∩ ({∅} × 𝐵)) = ∅) → (𝐴 ⊔ 𝐵) ≈ (({1o} × 𝐴) ∪ ({∅} × 𝐵))) | |
13 | 11, 12 | mp3an3 1304 | . . . 4 ⊢ ((𝐴 ≈ ({1o} × 𝐴) ∧ 𝐵 ≈ ({∅} × 𝐵)) → (𝐴 ⊔ 𝐵) ≈ (({1o} × 𝐴) ∪ ({∅} × 𝐵))) |
14 | 7, 8, 13 | syl2an 287 | . . 3 ⊢ ((({1o} × 𝐴) ≈ 𝐴 ∧ ({∅} × 𝐵) ≈ 𝐵) → (𝐴 ⊔ 𝐵) ≈ (({1o} × 𝐴) ∪ ({∅} × 𝐵))) |
15 | 3, 6, 14 | syl2an 287 | . 2 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ⊔ 𝐵) ≈ (({1o} × 𝐴) ∪ ({∅} × 𝐵))) |
16 | df-dju 6923 | . . 3 ⊢ (𝐵 ⊔ 𝐴) = (({∅} × 𝐵) ∪ ({1o} × 𝐴)) | |
17 | 16 | equncomi 3222 | . 2 ⊢ (𝐵 ⊔ 𝐴) = (({1o} × 𝐴) ∪ ({∅} × 𝐵)) |
18 | 15, 17 | breqtrrdi 3970 | 1 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ⊔ 𝐵) ≈ (𝐵 ⊔ 𝐴)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 103 = wceq 1331 ∈ wcel 1480 Vcvv 2686 ∪ cun 3069 ∩ cin 3070 ∅c0 3363 {csn 3527 class class class wbr 3929 × cxp 4537 1oc1o 6306 ≈ cen 6632 ⊔ cdju 6922 |
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-13 1491 ax-14 1492 ax-17 1506 ax-i9 1510 ax-ial 1514 ax-i5r 1515 ax-ext 2121 ax-coll 4043 ax-sep 4046 ax-nul 4054 ax-pow 4098 ax-pr 4131 ax-un 4355 |
This theorem depends on definitions: df-bi 116 df-3an 964 df-tru 1334 df-fal 1337 df-nf 1437 df-sb 1736 df-eu 2002 df-mo 2003 df-clab 2126 df-cleq 2132 df-clel 2135 df-nfc 2270 df-ne 2309 df-ral 2421 df-rex 2422 df-reu 2423 df-rab 2425 df-v 2688 df-sbc 2910 df-csb 3004 df-dif 3073 df-un 3075 df-in 3077 df-ss 3084 df-nul 3364 df-pw 3512 df-sn 3533 df-pr 3534 df-op 3536 df-uni 3737 df-int 3772 df-iun 3815 df-br 3930 df-opab 3990 df-mpt 3991 df-tr 4027 df-id 4215 df-iord 4288 df-on 4290 df-suc 4293 df-xp 4545 df-rel 4546 df-cnv 4547 df-co 4548 df-dm 4549 df-rn 4550 df-res 4551 df-ima 4552 df-iota 5088 df-fun 5125 df-fn 5126 df-f 5127 df-f1 5128 df-fo 5129 df-f1o 5130 df-fv 5131 df-1st 6038 df-2nd 6039 df-1o 6313 df-er 6429 df-en 6635 df-dju 6923 df-inl 6932 df-inr 6933 |
This theorem is referenced by: (None) |
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