Proof of Theorem disjdifprg
| Step | Hyp | Ref
| Expression |
| 1 | | disjxsn 5137 |
. . . . . 6
⊢
Disj 𝑥 ∈
{∅}𝑥 |
| 2 | | simpr 484 |
. . . . . . . 8
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 = ∅) → 𝐵 = ∅) |
| 3 | | eqidd 2738 |
. . . . . . . 8
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 = ∅) → ∅ =
∅) |
| 4 | | id 22 |
. . . . . . . . . 10
⊢ (𝐵 ∈ 𝑊 → 𝐵 ∈ 𝑊) |
| 5 | | 0ex 5307 |
. . . . . . . . . . 11
⊢ ∅
∈ V |
| 6 | 5 | a1i 11 |
. . . . . . . . . 10
⊢ (𝐵 ∈ 𝑊 → ∅ ∈ V) |
| 7 | 4, 6 | preqsnd 4859 |
. . . . . . . . 9
⊢ (𝐵 ∈ 𝑊 → ({𝐵, ∅} = {∅} ↔ (𝐵 = ∅ ∧ ∅ =
∅))) |
| 8 | 7 | adantr 480 |
. . . . . . . 8
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 = ∅) → ({𝐵, ∅} = {∅} ↔ (𝐵 = ∅ ∧ ∅ =
∅))) |
| 9 | 2, 3, 8 | mpbir2and 713 |
. . . . . . 7
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 = ∅) → {𝐵, ∅} = {∅}) |
| 10 | 9 | disjeq1d 5118 |
. . . . . 6
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 = ∅) → (Disj 𝑥 ∈ {𝐵, ∅}𝑥 ↔ Disj 𝑥 ∈ {∅}𝑥)) |
| 11 | 1, 10 | mpbiri 258 |
. . . . 5
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 = ∅) → Disj 𝑥 ∈ {𝐵, ∅}𝑥) |
| 12 | | in0 4395 |
. . . . . 6
⊢ (𝐵 ∩ ∅) =
∅ |
| 13 | | elex 3501 |
. . . . . . . 8
⊢ (𝐵 ∈ 𝑊 → 𝐵 ∈ V) |
| 14 | 13 | adantr 480 |
. . . . . . 7
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 ≠ ∅) → 𝐵 ∈ V) |
| 15 | 5 | a1i 11 |
. . . . . . 7
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 ≠ ∅) → ∅ ∈
V) |
| 16 | | simpr 484 |
. . . . . . 7
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 ≠ ∅) → 𝐵 ≠ ∅) |
| 17 | | id 22 |
. . . . . . . 8
⊢ (𝑥 = 𝐵 → 𝑥 = 𝐵) |
| 18 | | id 22 |
. . . . . . . 8
⊢ (𝑥 = ∅ → 𝑥 = ∅) |
| 19 | 17, 18 | disjprg 5139 |
. . . . . . 7
⊢ ((𝐵 ∈ V ∧ ∅ ∈ V
∧ 𝐵 ≠ ∅)
→ (Disj 𝑥
∈ {𝐵, ∅}𝑥 ↔ (𝐵 ∩ ∅) = ∅)) |
| 20 | 14, 15, 16, 19 | syl3anc 1373 |
. . . . . 6
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 ≠ ∅) → (Disj 𝑥 ∈ {𝐵, ∅}𝑥 ↔ (𝐵 ∩ ∅) = ∅)) |
| 21 | 12, 20 | mpbiri 258 |
. . . . 5
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐵 ≠ ∅) → Disj 𝑥 ∈ {𝐵, ∅}𝑥) |
| 22 | 11, 21 | pm2.61dane 3029 |
. . . 4
⊢ (𝐵 ∈ 𝑊 → Disj 𝑥 ∈ {𝐵, ∅}𝑥) |
| 23 | 22 | ad2antlr 727 |
. . 3
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 = ∅) → Disj 𝑥 ∈ {𝐵, ∅}𝑥) |
| 24 | | difeq2 4120 |
. . . . . . 7
⊢ (𝐴 = ∅ → (𝐵 ∖ 𝐴) = (𝐵 ∖ ∅)) |
| 25 | | dif0 4378 |
. . . . . . 7
⊢ (𝐵 ∖ ∅) = 𝐵 |
| 26 | 24, 25 | eqtrdi 2793 |
. . . . . 6
⊢ (𝐴 = ∅ → (𝐵 ∖ 𝐴) = 𝐵) |
| 27 | | id 22 |
. . . . . 6
⊢ (𝐴 = ∅ → 𝐴 = ∅) |
| 28 | 26, 27 | preq12d 4741 |
. . . . 5
⊢ (𝐴 = ∅ → {(𝐵 ∖ 𝐴), 𝐴} = {𝐵, ∅}) |
| 29 | 28 | disjeq1d 5118 |
. . . 4
⊢ (𝐴 = ∅ → (Disj
𝑥 ∈ {(𝐵 ∖ 𝐴), 𝐴}𝑥 ↔ Disj 𝑥 ∈ {𝐵, ∅}𝑥)) |
| 30 | 29 | adantl 481 |
. . 3
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 = ∅) → (Disj 𝑥 ∈ {(𝐵 ∖ 𝐴), 𝐴}𝑥 ↔ Disj 𝑥 ∈ {𝐵, ∅}𝑥)) |
| 31 | 23, 30 | mpbird 257 |
. 2
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 = ∅) → Disj 𝑥 ∈ {(𝐵 ∖ 𝐴), 𝐴}𝑥) |
| 32 | | disjdifr 4473 |
. . 3
⊢ ((𝐵 ∖ 𝐴) ∩ 𝐴) = ∅ |
| 33 | | difexg 5329 |
. . . . 5
⊢ (𝐵 ∈ 𝑊 → (𝐵 ∖ 𝐴) ∈ V) |
| 34 | 33 | ad2antlr 727 |
. . . 4
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ ¬ 𝐴 = ∅) → (𝐵 ∖ 𝐴) ∈ V) |
| 35 | | elex 3501 |
. . . . 5
⊢ (𝐴 ∈ 𝑉 → 𝐴 ∈ V) |
| 36 | 35 | ad2antrr 726 |
. . . 4
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ ¬ 𝐴 = ∅) → 𝐴 ∈ V) |
| 37 | | ssid 4006 |
. . . . . 6
⊢ (𝐵 ∖ 𝐴) ⊆ (𝐵 ∖ 𝐴) |
| 38 | | ssdifeq0 4487 |
. . . . . . . 8
⊢ (𝐴 ⊆ (𝐵 ∖ 𝐴) ↔ 𝐴 = ∅) |
| 39 | 38 | notbii 320 |
. . . . . . 7
⊢ (¬
𝐴 ⊆ (𝐵 ∖ 𝐴) ↔ ¬ 𝐴 = ∅) |
| 40 | | nssne2 4047 |
. . . . . . 7
⊢ (((𝐵 ∖ 𝐴) ⊆ (𝐵 ∖ 𝐴) ∧ ¬ 𝐴 ⊆ (𝐵 ∖ 𝐴)) → (𝐵 ∖ 𝐴) ≠ 𝐴) |
| 41 | 39, 40 | sylan2br 595 |
. . . . . 6
⊢ (((𝐵 ∖ 𝐴) ⊆ (𝐵 ∖ 𝐴) ∧ ¬ 𝐴 = ∅) → (𝐵 ∖ 𝐴) ≠ 𝐴) |
| 42 | 37, 41 | mpan 690 |
. . . . 5
⊢ (¬
𝐴 = ∅ → (𝐵 ∖ 𝐴) ≠ 𝐴) |
| 43 | 42 | adantl 481 |
. . . 4
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ ¬ 𝐴 = ∅) → (𝐵 ∖ 𝐴) ≠ 𝐴) |
| 44 | | id 22 |
. . . . 5
⊢ (𝑥 = (𝐵 ∖ 𝐴) → 𝑥 = (𝐵 ∖ 𝐴)) |
| 45 | | id 22 |
. . . . 5
⊢ (𝑥 = 𝐴 → 𝑥 = 𝐴) |
| 46 | 44, 45 | disjprg 5139 |
. . . 4
⊢ (((𝐵 ∖ 𝐴) ∈ V ∧ 𝐴 ∈ V ∧ (𝐵 ∖ 𝐴) ≠ 𝐴) → (Disj 𝑥 ∈ {(𝐵 ∖ 𝐴), 𝐴}𝑥 ↔ ((𝐵 ∖ 𝐴) ∩ 𝐴) = ∅)) |
| 47 | 34, 36, 43, 46 | syl3anc 1373 |
. . 3
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ ¬ 𝐴 = ∅) → (Disj 𝑥 ∈ {(𝐵 ∖ 𝐴), 𝐴}𝑥 ↔ ((𝐵 ∖ 𝐴) ∩ 𝐴) = ∅)) |
| 48 | 32, 47 | mpbiri 258 |
. 2
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ ¬ 𝐴 = ∅) → Disj 𝑥 ∈ {(𝐵 ∖ 𝐴), 𝐴}𝑥) |
| 49 | 31, 48 | pm2.61dan 813 |
1
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → Disj 𝑥 ∈ {(𝐵 ∖ 𝐴), 𝐴}𝑥) |