Proof of Theorem omlem2
| Step | Hyp | Ref
| Expression |
| 1 | | ax-a2 30 |
. . 3
((a ∪ b)⊥ ∪ a) = (a ∪
(a ∪ b)⊥ ) |
| 2 | | anor2 81 |
. . 3
(a⊥ ∩ (a ∪ b)) =
(a ∪ (a ∪ b)⊥ )⊥ |
| 3 | 1, 2 | 2or 67 |
. 2
(((a ∪ b)⊥ ∪ a) ∪ (a⊥ ∩ (a ∪ b))) =
((a ∪ (a ∪ b)⊥ ) ∪ (a ∪ (a ∪
b)⊥ )⊥
) |
| 4 | | ax-a3 31 |
. . 3
(((a ∪ b)⊥ ∪ a) ∪ (a⊥ ∩ (a ∪ b))) =
((a ∪ b)⊥ ∪ (a ∪ (a⊥ ∩ (a ∪ b)))) |
| 5 | 4 | ax-r1 34 |
. 2
((a ∪ b)⊥ ∪ (a ∪ (a⊥ ∩ (a ∪ b)))) =
(((a ∪ b)⊥ ∪ a) ∪ (a⊥ ∩ (a ∪ b))) |
| 6 | | df-t 40 |
. 2
1 = ((a ∪ (a ∪ b)⊥ ) ∪ (a ∪ (a ∪
b)⊥ )⊥
) |
| 7 | 3, 5, 6 | 3tr1 60 |
1
((a ∪ b)⊥ ∪ (a ∪ (a⊥ ∩ (a ∪ b)))) =
1 |