Proof of Theorem nom53
| Step | Hyp | Ref
| Expression |
| 1 | | ancom 68 |
. . . . . . . 8
(b⊥ ∩ a⊥ ) = (a⊥ ∩ b⊥ ) |
| 2 | | anor3 82 |
. . . . . . . 8
(a⊥ ∩ b⊥ ) = (a ∪ b)⊥ |
| 3 | 1, 2 | ax-r2 35 |
. . . . . . 7
(b⊥ ∩ a⊥ ) = (a ∪ b)⊥ |
| 4 | 3 | ax-r1 34 |
. . . . . 6
(a ∪ b)⊥ = (b⊥ ∩ a⊥ ) |
| 5 | 4 | lor 66 |
. . . . 5
(b⊥ ⊥
∪ (a ∪ b)⊥ ) = (b⊥ ⊥ ∪
(b⊥ ∩ a⊥ )) |
| 6 | 4 | ax-r4 36 |
. . . . . 6
(a ∪ b)⊥ ⊥ = (b⊥ ∩ a⊥ )⊥ |
| 7 | 4 | lan 70 |
. . . . . 6
(b⊥ ∩ (a ∪ b)⊥ ) = (b⊥ ∩ (b⊥ ∩ a⊥ )) |
| 8 | 6, 7 | 2or 67 |
. . . . 5
((a ∪ b)⊥ ⊥ ∪
(b⊥ ∩ (a ∪ b)⊥ )) = ((b⊥ ∩ a⊥ )⊥ ∪
(b⊥ ∩ (b⊥ ∩ a⊥ ))) |
| 9 | 5, 8 | 2an 72 |
. . . 4
((b⊥ ⊥
∪ (a ∪ b)⊥ ) ∩ ((a ∪ b)⊥ ⊥ ∪
(b⊥ ∩ (a ∪ b)⊥ ))) = ((b⊥ ⊥ ∪
(b⊥ ∩ a⊥ )) ∩ ((b⊥ ∩ a⊥ )⊥ ∪
(b⊥ ∩ (b⊥ ∩ a⊥ )))) |
| 10 | | df-id4 52 |
. . . 4
(b⊥ ≡4
(a ∪ b)⊥ ) = ((b⊥ ⊥ ∪
(a ∪ b)⊥ ) ∩ ((a ∪ b)⊥ ⊥ ∪
(b⊥ ∩ (a ∪ b)⊥ ))) |
| 11 | | df-id4 52 |
. . . 4
(b⊥ ≡4
(b⊥ ∩ a⊥ )) = ((b⊥ ⊥ ∪
(b⊥ ∩ a⊥ )) ∩ ((b⊥ ∩ a⊥ )⊥ ∪
(b⊥ ∩ (b⊥ ∩ a⊥ )))) |
| 12 | 9, 10, 11 | 3tr1 60 |
. . 3
(b⊥ ≡4
(a ∪ b)⊥ ) = (b⊥ ≡4 (b⊥ ∩ a⊥ )) |
| 13 | | nom24 309 |
. . 3
(b⊥ ≡4
(b⊥ ∩ a⊥ )) = (b⊥ →1 a⊥ ) |
| 14 | 12, 13 | ax-r2 35 |
. 2
(b⊥ ≡4
(a ∪ b)⊥ ) = (b⊥ →1 a⊥ ) |
| 15 | | nomcon3 296 |
. 2
((a ∪ b) ≡3 b) = (b⊥ ≡4 (a ∪ b)⊥ ) |
| 16 | | i2i1 259 |
. 2
(a →2 b) = (b⊥ →1 a⊥ ) |
| 17 | 14, 15, 16 | 3tr1 60 |
1
((a ∪ b) ≡3 b) = (a
→2 b) |