Proof of Theorem 3vded11
| Step | Hyp | Ref
| Expression |
| 1 | | le1 138 |
. . 3
(c →1 (b →1 a)) ≤ 1 |
| 2 | | df-t 40 |
. . . . 5
1 = ((b ∪ c⊥ ) ∪ (b ∪ c⊥ )⊥ ) |
| 3 | | ancom 68 |
. . . . . . . 8
(c ∩ b⊥ ) = (b⊥ ∩ c) |
| 4 | | anor2 81 |
. . . . . . . 8
(b⊥ ∩ c) = (b ∪
c⊥
)⊥ |
| 5 | 3, 4 | ax-r2 35 |
. . . . . . 7
(c ∩ b⊥ ) = (b ∪ c⊥ )⊥ |
| 6 | 5 | lor 66 |
. . . . . 6
((b ∪ c⊥ ) ∪ (c ∩ b⊥ )) = ((b ∪ c⊥ ) ∪ (b ∪ c⊥ )⊥ ) |
| 7 | 6 | ax-r1 34 |
. . . . 5
((b ∪ c⊥ ) ∪ (b ∪ c⊥ )⊥ ) =
((b ∪ c⊥ ) ∪ (c ∩ b⊥ )) |
| 8 | | ax-a3 31 |
. . . . 5
((b ∪ c⊥ ) ∪ (c ∩ b⊥ )) = (b ∪ (c⊥ ∪ (c ∩ b⊥ ))) |
| 9 | 2, 7, 8 | 3tr 62 |
. . . 4
1 = (b ∪ (c⊥ ∪ (c ∩ b⊥ ))) |
| 10 | | 3vded11.1 |
. . . . 5
b ≤ (c →1 (b →1 a)) |
| 11 | | leo 150 |
. . . . . . . . 9
b⊥ ≤ (b⊥ ∪ (b ∩ a)) |
| 12 | | df-i1 43 |
. . . . . . . . . 10
(b →1 a) = (b⊥ ∪ (b ∩ a)) |
| 13 | 12 | ax-r1 34 |
. . . . . . . . 9
(b⊥ ∪ (b ∩ a)) =
(b →1 a) |
| 14 | 11, 13 | lbtr 131 |
. . . . . . . 8
b⊥ ≤ (b →1 a) |
| 15 | 14 | lelan 159 |
. . . . . . 7
(c ∩ b⊥ ) ≤ (c ∩ (b
→1 a)) |
| 16 | 15 | lelor 158 |
. . . . . 6
(c⊥ ∪ (c ∩ b⊥ )) ≤ (c⊥ ∪ (c ∩ (b
→1 a))) |
| 17 | | df-i1 43 |
. . . . . . 7
(c →1 (b →1 a)) = (c⊥ ∪ (c ∩ (b
→1 a))) |
| 18 | 17 | ax-r1 34 |
. . . . . 6
(c⊥ ∪ (c ∩ (b
→1 a))) = (c →1 (b →1 a)) |
| 19 | 16, 18 | lbtr 131 |
. . . . 5
(c⊥ ∪ (c ∩ b⊥ )) ≤ (c →1 (b →1 a)) |
| 20 | 10, 19 | lel2or 162 |
. . . 4
(b ∪ (c⊥ ∪ (c ∩ b⊥ ))) ≤ (c →1 (b →1 a)) |
| 21 | 9, 20 | bltr 130 |
. . 3
1 ≤ (c →1 (b →1 a)) |
| 22 | 1, 21 | lebi 137 |
. 2
(c →1 (b →1 a)) = 1 |
| 23 | 22 | u1lemle2 697 |
1
c ≤ (b →1 a) |