Proof of Theorem negantlem3
| Step | Hyp | Ref
| Expression |
| 1 | | leo 150 |
. . . 4
a⊥ ≤ (a⊥ ∪ (a ∩ c)) |
| 2 | | df-i1 43 |
. . . . . 6
(a →1 c) = (a⊥ ∪ (a ∩ c)) |
| 3 | 2 | ax-r1 34 |
. . . . 5
(a⊥ ∪ (a ∩ c)) =
(a →1 c) |
| 4 | | negant.1 |
. . . . 5
(a →1 c) = (b
→1 c) |
| 5 | 3, 4 | ax-r2 35 |
. . . 4
(a⊥ ∪ (a ∩ c)) =
(b →1 c) |
| 6 | 1, 5 | lbtr 131 |
. . 3
a⊥ ≤ (b →1 c) |
| 7 | 6 | leran 145 |
. 2
(a⊥ ∩ c) ≤ ((b
→1 c) ∩ c) |
| 8 | | lea 152 |
. . . 4
(b ∩ c) ≤ b |
| 9 | 8 | leror 144 |
. . 3
((b ∩ c) ∪ (b⊥ ∩ c)) ≤ (b
∪ (b⊥ ∩ c)) |
| 10 | | u1lemab 592 |
. . 3
((b →1 c) ∩ c) =
((b ∩ c) ∪ (b⊥ ∩ c)) |
| 11 | | df-i1 43 |
. . . 4
(b⊥ →1
c) = (b⊥ ⊥ ∪
(b⊥ ∩ c)) |
| 12 | | ax-a1 29 |
. . . . . 6
b = b⊥ ⊥ |
| 13 | 12 | ax-r5 37 |
. . . . 5
(b ∪ (b⊥ ∩ c)) = (b⊥ ⊥ ∪
(b⊥ ∩ c)) |
| 14 | 13 | ax-r1 34 |
. . . 4
(b⊥ ⊥
∪ (b⊥ ∩ c)) = (b ∪
(b⊥ ∩ c)) |
| 15 | 11, 14 | ax-r2 35 |
. . 3
(b⊥ →1
c) = (b ∪ (b⊥ ∩ c)) |
| 16 | 9, 10, 15 | le3tr1 132 |
. 2
((b →1 c) ∩ c) ≤
(b⊥ →1
c) |
| 17 | 7, 16 | letr 129 |
1
(a⊥ ∩ c) ≤ (b⊥ →1 c) |