Proof of Theorem wr2
| Step | Hyp | Ref
| Expression |
| 1 | | wr2.2 |
. . 3
(b ≡ c) = 1 |
| 2 | | dfb 86 |
. . . . 5
(b ≡ c) = ((b ∩
c) ∪ (b⊥ ∩ c⊥ )) |
| 3 | 2 | rbi 90 |
. . . 4
((b ≡ c) ≡ ((a
∩ c) ∪ (b⊥ ∩ c⊥ ))) = (((b ∩ c) ∪
(b⊥ ∩ c⊥ )) ≡ ((a ∩ c) ∪
(b⊥ ∩ c⊥ ))) |
| 4 | | wr2.1 |
. . . . . . 7
(a ≡ b) = 1 |
| 5 | 4 | wr1 189 |
. . . . . 6
(b ≡ a) = 1 |
| 6 | 5 | wran 351 |
. . . . 5
((b ∩ c) ≡ (a
∩ c)) = 1 |
| 7 | 6 | wr5-2v 348 |
. . . 4
(((b ∩ c) ∪ (b⊥ ∩ c⊥ )) ≡ ((a ∩ c) ∪
(b⊥ ∩ c⊥ ))) = 1 |
| 8 | 3, 7 | ax-r2 35 |
. . 3
((b ≡ c) ≡ ((a
∩ c) ∪ (b⊥ ∩ c⊥ ))) = 1 |
| 9 | 1, 8 | wwbmp 197 |
. 2
((a ∩ c) ∪ (b⊥ ∩ c⊥ )) = 1 |
| 10 | | dfb 86 |
. . . 4
(a ≡ c) = ((a ∩
c) ∪ (a⊥ ∩ c⊥ )) |
| 11 | 10 | rbi 90 |
. . 3
((a ≡ c) ≡ ((a
∩ c) ∪ (b⊥ ∩ c⊥ ))) = (((a ∩ c) ∪
(a⊥ ∩ c⊥ )) ≡ ((a ∩ c) ∪
(b⊥ ∩ c⊥ ))) |
| 12 | 4 | wr4 191 |
. . . . 5
(a⊥ ≡ b⊥ ) = 1 |
| 13 | 12 | wran 351 |
. . . 4
((a⊥ ∩ c⊥ ) ≡ (b⊥ ∩ c⊥ )) = 1 |
| 14 | 13 | wlor 350 |
. . 3
(((a ∩ c) ∪ (a⊥ ∩ c⊥ )) ≡ ((a ∩ c) ∪
(b⊥ ∩ c⊥ ))) = 1 |
| 15 | 11, 14 | ax-r2 35 |
. 2
((a ≡ c) ≡ ((a
∩ c) ∪ (b⊥ ∩ c⊥ ))) = 1 |
| 16 | 9, 15 | wwbmpr 198 |
1
(a ≡ c) = 1 |