Proof of Theorem wdf-c1
| Step | Hyp | Ref
| Expression |
| 1 | | cmtrcom 182 |
. 2
C (a, b) = C (b, a) |
| 2 | | df-cmtr 126 |
. 2
C (b, a) = (((b ∩
a) ∪ (b ∩ a⊥ )) ∪ ((b⊥ ∩ a) ∪ (b⊥ ∩ a⊥ ))) |
| 3 | | df-t 40 |
. . . . 5
1 = (b ∪ b⊥ ) |
| 4 | 3 | bi1 110 |
. . . 4
(1 ≡ (b ∪ b⊥ )) = 1 |
| 5 | | wdf-c1.1 |
. . . . . 6
(a ≡ ((a ∩ b) ∪
(a ∩ b⊥ ))) = 1 |
| 6 | 5 | wcomlem 364 |
. . . . 5
(b ≡ ((b ∩ a) ∪
(b ∩ a⊥ ))) = 1 |
| 7 | | ax-a1 29 |
. . . . . . . . . . 11
b = b⊥ ⊥ |
| 8 | 7 | lan 70 |
. . . . . . . . . 10
(a ∩ b) = (a ∩
b⊥ ⊥
) |
| 9 | 8 | ax-r5 37 |
. . . . . . . . 9
((a ∩ b) ∪ (a
∩ b⊥ )) = ((a ∩ b⊥ ⊥ ) ∪
(a ∩ b⊥ )) |
| 10 | | ax-a2 30 |
. . . . . . . . 9
((a ∩ b⊥ ⊥ ) ∪
(a ∩ b⊥ )) = ((a ∩ b⊥ ) ∪ (a ∩ b⊥ ⊥ )) |
| 11 | 9, 10 | ax-r2 35 |
. . . . . . . 8
((a ∩ b) ∪ (a
∩ b⊥ )) = ((a ∩ b⊥ ) ∪ (a ∩ b⊥ ⊥ )) |
| 12 | 11 | bi1 110 |
. . . . . . 7
(((a ∩ b) ∪ (a
∩ b⊥ )) ≡
((a ∩ b⊥ ) ∪ (a ∩ b⊥ ⊥ ))) =
1 |
| 13 | 5, 12 | wr2 353 |
. . . . . 6
(a ≡ ((a ∩ b⊥ ) ∪ (a ∩ b⊥ ⊥ ))) =
1 |
| 14 | 13 | wcomlem 364 |
. . . . 5
(b⊥ ≡ ((b⊥ ∩ a) ∪ (b⊥ ∩ a⊥ ))) = 1 |
| 15 | 6, 14 | w2or 354 |
. . . 4
((b ∪ b⊥ ) ≡ (((b ∩ a) ∪
(b ∩ a⊥ )) ∪ ((b⊥ ∩ a) ∪ (b⊥ ∩ a⊥ )))) = 1 |
| 16 | 4, 15 | wr2 353 |
. . 3
(1 ≡ (((b ∩ a) ∪ (b
∩ a⊥ )) ∪
((b⊥ ∩ a) ∪ (b⊥ ∩ a⊥ )))) = 1 |
| 17 | 16 | wr3 190 |
. 2
(((b ∩ a) ∪ (b
∩ a⊥ )) ∪
((b⊥ ∩ a) ∪ (b⊥ ∩ a⊥ ))) = 1 |
| 18 | 1, 2, 17 | 3tr 62 |
1
C (a, b) = 1 |