Proof of Theorem bnj1279
| Step | Hyp | Ref
| Expression |
| 1 | | n0 4333 |
. . . . . . . 8
⊢ ((
pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅ ↔ ∃𝑦 𝑦 ∈ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸)) |
| 2 | | elin 3947 |
. . . . . . . . 9
⊢ (𝑦 ∈ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ↔ (𝑦 ∈ pred(𝑥, 𝐴, 𝑅) ∧ 𝑦 ∈ 𝐸)) |
| 3 | 2 | exbii 1848 |
. . . . . . . 8
⊢
(∃𝑦 𝑦 ∈ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ↔ ∃𝑦(𝑦 ∈ pred(𝑥, 𝐴, 𝑅) ∧ 𝑦 ∈ 𝐸)) |
| 4 | 1, 3 | sylbb 219 |
. . . . . . 7
⊢ ((
pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅ → ∃𝑦(𝑦 ∈ pred(𝑥, 𝐴, 𝑅) ∧ 𝑦 ∈ 𝐸)) |
| 5 | | df-bnj14 34725 |
. . . . . . . . 9
⊢
pred(𝑥, 𝐴, 𝑅) = {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑥} |
| 6 | 5 | bnj1538 34891 |
. . . . . . . 8
⊢ (𝑦 ∈ pred(𝑥, 𝐴, 𝑅) → 𝑦𝑅𝑥) |
| 7 | 6 | anim1i 615 |
. . . . . . 7
⊢ ((𝑦 ∈ pred(𝑥, 𝐴, 𝑅) ∧ 𝑦 ∈ 𝐸) → (𝑦𝑅𝑥 ∧ 𝑦 ∈ 𝐸)) |
| 8 | 4, 7 | bnj593 34781 |
. . . . . 6
⊢ ((
pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅ → ∃𝑦(𝑦𝑅𝑥 ∧ 𝑦 ∈ 𝐸)) |
| 9 | 8 | 3ad2ant3 1135 |
. . . . 5
⊢ ((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) → ∃𝑦(𝑦𝑅𝑥 ∧ 𝑦 ∈ 𝐸)) |
| 10 | | nfv 1914 |
. . . . . . 7
⊢
Ⅎ𝑦 𝑥 ∈ 𝐸 |
| 11 | | nfra1 3270 |
. . . . . . 7
⊢
Ⅎ𝑦∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 |
| 12 | | nfv 1914 |
. . . . . . 7
⊢
Ⅎ𝑦( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅ |
| 13 | 10, 11, 12 | nf3an 1901 |
. . . . . 6
⊢
Ⅎ𝑦(𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) |
| 14 | 13 | nf5ri 2196 |
. . . . 5
⊢ ((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) → ∀𝑦(𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅)) |
| 15 | 9, 14 | bnj1275 34849 |
. . . 4
⊢ ((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) → ∃𝑦((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) ∧ 𝑦𝑅𝑥 ∧ 𝑦 ∈ 𝐸)) |
| 16 | | simp2 1137 |
. . . 4
⊢ (((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) ∧ 𝑦𝑅𝑥 ∧ 𝑦 ∈ 𝐸) → 𝑦𝑅𝑥) |
| 17 | | simp12 1205 |
. . . . 5
⊢ (((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) ∧ 𝑦𝑅𝑥 ∧ 𝑦 ∈ 𝐸) → ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥) |
| 18 | | simp3 1138 |
. . . . 5
⊢ (((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) ∧ 𝑦𝑅𝑥 ∧ 𝑦 ∈ 𝐸) → 𝑦 ∈ 𝐸) |
| 19 | 17, 18 | bnj1294 34853 |
. . . 4
⊢ (((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) ∧ 𝑦𝑅𝑥 ∧ 𝑦 ∈ 𝐸) → ¬ 𝑦𝑅𝑥) |
| 20 | 15, 16, 19 | bnj1304 34855 |
. . 3
⊢ ¬
(𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥 ∧ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) |
| 21 | 20 | bnj1224 34837 |
. 2
⊢ ((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥) → ¬ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅) |
| 22 | | nne 2937 |
. 2
⊢ (¬ (
pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) ≠ ∅ ↔ ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) = ∅) |
| 23 | 21, 22 | sylib 218 |
1
⊢ ((𝑥 ∈ 𝐸 ∧ ∀𝑦 ∈ 𝐸 ¬ 𝑦𝑅𝑥) → ( pred(𝑥, 𝐴, 𝑅) ∩ 𝐸) = ∅) |