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Mirrors > Home > ILE Home > Th. List > disji2 | GIF version |
Description: Property of a disjoint collection: if 𝐵(𝑋) = 𝐶 and 𝐵(𝑌) = 𝐷, and 𝑋 ≠ 𝑌, then 𝐶 and 𝐷 are disjoint. (Contributed by Mario Carneiro, 14-Nov-2016.) |
Ref | Expression |
---|---|
disji.1 | ⊢ (𝑥 = 𝑋 → 𝐵 = 𝐶) |
disji.2 | ⊢ (𝑥 = 𝑌 → 𝐵 = 𝐷) |
Ref | Expression |
---|---|
disji2 | ⊢ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ (𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ 𝑋 ≠ 𝑌) → (𝐶 ∩ 𝐷) = ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | disjnims 4010 | . . 3 ⊢ (Disj 𝑥 ∈ 𝐴 𝐵 → ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (𝑦 ≠ 𝑧 → (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅)) | |
2 | neeq1 2373 | . . . . 5 ⊢ (𝑦 = 𝑋 → (𝑦 ≠ 𝑧 ↔ 𝑋 ≠ 𝑧)) | |
3 | nfcv 2332 | . . . . . . . 8 ⊢ Ⅎ𝑥𝑋 | |
4 | nfcv 2332 | . . . . . . . 8 ⊢ Ⅎ𝑥𝐶 | |
5 | disji.1 | . . . . . . . 8 ⊢ (𝑥 = 𝑋 → 𝐵 = 𝐶) | |
6 | 3, 4, 5 | csbhypf 3110 | . . . . . . 7 ⊢ (𝑦 = 𝑋 → ⦋𝑦 / 𝑥⦌𝐵 = 𝐶) |
7 | 6 | ineq1d 3350 | . . . . . 6 ⊢ (𝑦 = 𝑋 → (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = (𝐶 ∩ ⦋𝑧 / 𝑥⦌𝐵)) |
8 | 7 | eqeq1d 2198 | . . . . 5 ⊢ (𝑦 = 𝑋 → ((⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅ ↔ (𝐶 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅)) |
9 | 2, 8 | imbi12d 234 | . . . 4 ⊢ (𝑦 = 𝑋 → ((𝑦 ≠ 𝑧 → (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅) ↔ (𝑋 ≠ 𝑧 → (𝐶 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅))) |
10 | neeq2 2374 | . . . . 5 ⊢ (𝑧 = 𝑌 → (𝑋 ≠ 𝑧 ↔ 𝑋 ≠ 𝑌)) | |
11 | nfcv 2332 | . . . . . . . 8 ⊢ Ⅎ𝑥𝑌 | |
12 | nfcv 2332 | . . . . . . . 8 ⊢ Ⅎ𝑥𝐷 | |
13 | disji.2 | . . . . . . . 8 ⊢ (𝑥 = 𝑌 → 𝐵 = 𝐷) | |
14 | 11, 12, 13 | csbhypf 3110 | . . . . . . 7 ⊢ (𝑧 = 𝑌 → ⦋𝑧 / 𝑥⦌𝐵 = 𝐷) |
15 | 14 | ineq2d 3351 | . . . . . 6 ⊢ (𝑧 = 𝑌 → (𝐶 ∩ ⦋𝑧 / 𝑥⦌𝐵) = (𝐶 ∩ 𝐷)) |
16 | 15 | eqeq1d 2198 | . . . . 5 ⊢ (𝑧 = 𝑌 → ((𝐶 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅ ↔ (𝐶 ∩ 𝐷) = ∅)) |
17 | 10, 16 | imbi12d 234 | . . . 4 ⊢ (𝑧 = 𝑌 → ((𝑋 ≠ 𝑧 → (𝐶 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅) ↔ (𝑋 ≠ 𝑌 → (𝐶 ∩ 𝐷) = ∅))) |
18 | 9, 17 | rspc2v 2869 | . . 3 ⊢ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) → (∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (𝑦 ≠ 𝑧 → (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅) → (𝑋 ≠ 𝑌 → (𝐶 ∩ 𝐷) = ∅))) |
19 | 1, 18 | mpan9 281 | . 2 ⊢ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ (𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴)) → (𝑋 ≠ 𝑌 → (𝐶 ∩ 𝐷) = ∅)) |
20 | 19 | 3impia 1202 | 1 ⊢ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ (𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ 𝑋 ≠ 𝑌) → (𝐶 ∩ 𝐷) = ∅) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 104 ∧ w3a 980 = wceq 1364 ∈ wcel 2160 ≠ wne 2360 ∀wral 2468 ⦋csb 3072 ∩ cin 3143 ∅c0 3437 Disj wdisj 3995 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 615 ax-in2 616 ax-io 710 ax-5 1458 ax-7 1459 ax-gen 1460 ax-ie1 1504 ax-ie2 1505 ax-8 1515 ax-10 1516 ax-11 1517 ax-i12 1518 ax-bndl 1520 ax-4 1521 ax-17 1537 ax-i9 1541 ax-ial 1545 ax-i5r 1546 ax-ext 2171 |
This theorem depends on definitions: df-bi 117 df-3an 982 df-tru 1367 df-fal 1370 df-nf 1472 df-sb 1774 df-eu 2041 df-mo 2042 df-clab 2176 df-cleq 2182 df-clel 2185 df-nfc 2321 df-ne 2361 df-ral 2473 df-rex 2474 df-reu 2475 df-rmo 2476 df-v 2754 df-sbc 2978 df-csb 3073 df-dif 3146 df-in 3150 df-nul 3438 df-disj 3996 |
This theorem is referenced by: (None) |
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