Proof of Theorem ud3lem3d
| Step | Hyp | Ref
| Expression |
| 1 | | df-i3 45 |
. . 3
(a →3 b) = (((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∪ (a ∩ (a⊥ ∪ b))) |
| 2 | | ud3lem3c 556 |
. . 3
((a →3 b)⊥ ∪ (a ∪ b)) =
(a ∪ b) |
| 3 | 1, 2 | 2an 72 |
. 2
((a →3 b) ∩ ((a
→3 b)⊥
∪ (a ∪ b))) = ((((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∪ (a ∩ (a⊥ ∪ b))) ∩ (a
∪ b)) |
| 4 | | comor1 443 |
. . . . . . 7
(a ∪ b) C a |
| 5 | 4 | comcom2 175 |
. . . . . 6
(a ∪ b) C a⊥ |
| 6 | | comor2 444 |
. . . . . 6
(a ∪ b) C b |
| 7 | 5, 6 | com2an 466 |
. . . . 5
(a ∪ b) C (a⊥ ∩ b) |
| 8 | 6 | comcom2 175 |
. . . . . 6
(a ∪ b) C b⊥ |
| 9 | 5, 8 | com2an 466 |
. . . . 5
(a ∪ b) C (a⊥ ∩ b⊥ ) |
| 10 | 7, 9 | com2or 465 |
. . . 4
(a ∪ b) C ((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) |
| 11 | 5, 6 | com2or 465 |
. . . . 5
(a ∪ b) C (a⊥ ∪ b) |
| 12 | 4, 11 | com2an 466 |
. . . 4
(a ∪ b) C (a
∩ (a⊥ ∪ b)) |
| 13 | 10, 12 | fh1r 455 |
. . 3
((((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∪ (a ∩ (a⊥ ∪ b))) ∩ (a
∪ b)) = ((((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∩ (a ∪ b))
∪ ((a ∩ (a⊥ ∪ b)) ∩ (a
∪ b))) |
| 14 | | coman1 177 |
. . . . . . . . 9
(a⊥ ∩ b) C a⊥ |
| 15 | 14 | comcom7 442 |
. . . . . . . 8
(a⊥ ∩ b) C a |
| 16 | | coman2 178 |
. . . . . . . 8
(a⊥ ∩ b) C b |
| 17 | 15, 16 | com2or 465 |
. . . . . . 7
(a⊥ ∩ b) C (a
∪ b) |
| 18 | 16 | comcom2 175 |
. . . . . . . 8
(a⊥ ∩ b) C b⊥ |
| 19 | 14, 18 | com2an 466 |
. . . . . . 7
(a⊥ ∩ b) C (a⊥ ∩ b⊥ ) |
| 20 | 17, 19 | fh2r 456 |
. . . . . 6
(((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∩ (a ∪ b)) =
(((a⊥ ∩ b) ∩ (a
∪ b)) ∪ ((a⊥ ∩ b⊥ ) ∩ (a ∪ b))) |
| 21 | | lear 153 |
. . . . . . . . . 10
(a⊥ ∩ b) ≤ b |
| 22 | | leor 151 |
. . . . . . . . . 10
b ≤ (a ∪ b) |
| 23 | 21, 22 | letr 129 |
. . . . . . . . 9
(a⊥ ∩ b) ≤ (a ∪
b) |
| 24 | 23 | df2le2 128 |
. . . . . . . 8
((a⊥ ∩ b) ∩ (a
∪ b)) = (a⊥ ∩ b) |
| 25 | | oran 79 |
. . . . . . . . . 10
(a ∪ b) = (a⊥ ∩ b⊥ )⊥ |
| 26 | 25 | lan 70 |
. . . . . . . . 9
((a⊥ ∩ b⊥ ) ∩ (a ∪ b)) =
((a⊥ ∩ b⊥ ) ∩ (a⊥ ∩ b⊥ )⊥ ) |
| 27 | | dff 93 |
. . . . . . . . . 10
0 = ((a⊥ ∩ b⊥ ) ∩ (a⊥ ∩ b⊥ )⊥ ) |
| 28 | 27 | ax-r1 34 |
. . . . . . . . 9
((a⊥ ∩ b⊥ ) ∩ (a⊥ ∩ b⊥ )⊥ ) =
0 |
| 29 | 26, 28 | ax-r2 35 |
. . . . . . . 8
((a⊥ ∩ b⊥ ) ∩ (a ∪ b)) =
0 |
| 30 | 24, 29 | 2or 67 |
. . . . . . 7
(((a⊥ ∩ b) ∩ (a
∪ b)) ∪ ((a⊥ ∩ b⊥ ) ∩ (a ∪ b))) =
((a⊥ ∩ b) ∪ 0) |
| 31 | | or0 94 |
. . . . . . 7
((a⊥ ∩ b) ∪ 0) = (a⊥ ∩ b) |
| 32 | 30, 31 | ax-r2 35 |
. . . . . 6
(((a⊥ ∩ b) ∩ (a
∪ b)) ∪ ((a⊥ ∩ b⊥ ) ∩ (a ∪ b))) =
(a⊥ ∩ b) |
| 33 | 20, 32 | ax-r2 35 |
. . . . 5
(((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∩ (a ∪ b)) =
(a⊥ ∩ b) |
| 34 | 33 | ax-r5 37 |
. . . 4
((((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∩ (a ∪ b))
∪ ((a ∩ (a⊥ ∪ b)) ∩ (a
∪ b))) = ((a⊥ ∩ b) ∪ ((a
∩ (a⊥ ∪ b)) ∩ (a
∪ b))) |
| 35 | | lea 152 |
. . . . . . 7
(a ∩ (a⊥ ∪ b)) ≤ a |
| 36 | | leo 150 |
. . . . . . 7
a ≤ (a ∪ b) |
| 37 | 35, 36 | letr 129 |
. . . . . 6
(a ∩ (a⊥ ∪ b)) ≤ (a
∪ b) |
| 38 | 37 | df2le2 128 |
. . . . 5
((a ∩ (a⊥ ∪ b)) ∩ (a
∪ b)) = (a ∩ (a⊥ ∪ b)) |
| 39 | 38 | lor 66 |
. . . 4
((a⊥ ∩ b) ∪ ((a
∩ (a⊥ ∪ b)) ∩ (a
∪ b))) = ((a⊥ ∩ b) ∪ (a
∩ (a⊥ ∪ b))) |
| 40 | 34, 39 | ax-r2 35 |
. . 3
((((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∩ (a ∪ b))
∪ ((a ∩ (a⊥ ∪ b)) ∩ (a
∪ b))) = ((a⊥ ∩ b) ∪ (a
∩ (a⊥ ∪ b))) |
| 41 | 13, 40 | ax-r2 35 |
. 2
((((a⊥ ∩ b) ∪ (a⊥ ∩ b⊥ )) ∪ (a ∩ (a⊥ ∪ b))) ∩ (a
∪ b)) = ((a⊥ ∩ b) ∪ (a
∩ (a⊥ ∪ b))) |
| 42 | 3, 41 | ax-r2 35 |
1
((a →3 b) ∩ ((a
→3 b)⊥
∪ (a ∪ b))) = ((a⊥ ∩ b) ∪ (a
∩ (a⊥ ∪ b))) |