Proof of Theorem abs1
Step | Hyp | Ref
| Expression |
1 | | df-ad 132 |
. . . . 5
⊦ ((𝜑 ⊕ (𝜑 &
𝜓)) ⧟ ~ (~ 𝜑 & ~ (𝜑 &
𝜓))) |
2 | 1 | lbi1 89 |
. . . 4
⊦ ((𝜑 ⊕ (𝜑 &
𝜓)) ⊸ ~ (~ 𝜑 & ~ (𝜑 &
𝜓))) |
3 | | ax-init 7 |
. . . . . . . . 9
⊦ (~ ~ 𝜑 ⅋ ~ 𝜑) |
4 | | ax-init 7 |
. . . . . . . . . . . 12
⊦ (~ (𝜑 & 𝜓) ⅋
(𝜑 & 𝜓)) |
5 | 4 | ax-eac1 33 |
. . . . . . . . . . 11
⊦ (~ (𝜑 & 𝜓) ⅋
𝜑) |
6 | 5 | dnid 23 |
. . . . . . . . . 10
⊦ (~ (𝜑 & 𝜓) ⅋ ~ ~
𝜑) |
7 | 6 | mdcoi 12 |
. . . . . . . . 9
⊦ (~ ~ 𝜑 ⅋ ~ (𝜑 &
𝜓)) |
8 | 3, 7 | ax-iac 32 |
. . . . . . . 8
⊦ (~ ~ 𝜑 ⅋ (~ 𝜑 & ~
(𝜑 & 𝜓))) |
9 | 8 | dnid 23 |
. . . . . . 7
⊦ (~ ~ 𝜑 ⅋ ~ ~ (~ 𝜑
& ~ (𝜑 & 𝜓))) |
10 | 9 | mdcoi 12 |
. . . . . 6
⊦ (~ ~ (~ 𝜑 & ~ (𝜑 &
𝜓)) ⅋ ~ ~ 𝜑) |
11 | 10 | dned 24 |
. . . . 5
⊦ (~ ~ (~ 𝜑 & ~ (𝜑 &
𝜓)) ⅋ 𝜑) |
12 | 11 | dfli2i 66 |
. . . 4
⊦ (~ (~ 𝜑 & ~ (𝜑 &
𝜓)) ⊸ 𝜑) |
13 | 2, 12 | syl 75 |
. . 3
⊦ ((𝜑 ⊕ (𝜑 &
𝜓)) ⊸ 𝜑) |
14 | | ax-init 7 |
. . . . . . 7
⊦ (~ (~ 𝜑 & ~ (𝜑 &
𝜓)) ⅋ (~ 𝜑
& ~ (𝜑 & 𝜓))) |
15 | 14 | eac1d 37 |
. . . . . 6
⊦ (~ (~ 𝜑 & ~ (𝜑 &
𝜓)) ⅋ ~ 𝜑) |
16 | 15 | mdcoi 12 |
. . . . 5
⊦ (~ 𝜑 ⅋ ~ (~ 𝜑 &
~ (𝜑 & 𝜓))) |
17 | 16 | dfli2i 66 |
. . . 4
⊦ (𝜑
⊸ ~ (~ 𝜑 & ~ (𝜑 & 𝜓))) |
18 | 17, 1 | lb2s 68 |
. . 3
⊦ (𝜑
⊸ (𝜑 ⊕ (𝜑 & 𝜓))) |
19 | 13, 18 | iaci 36 |
. 2
⊦ (((𝜑 ⊕ (𝜑 &
𝜓)) ⊸ 𝜑)
& (𝜑 ⊸ (𝜑 ⊕ (𝜑 &
𝜓)))) |
20 | | dflb 93 |
. 2
⊦ (((𝜑 ⊕ (𝜑 &
𝜓)) ⧟ 𝜑)
⧟ (((𝜑 ⊕ (𝜑 & 𝜓)) ⊸
𝜑) & (𝜑
⊸ (𝜑 ⊕ (𝜑 & 𝜓))))) |
21 | 19, 20 | lb2i 60 |
1
⊦ ((𝜑 ⊕ (𝜑 &
𝜓)) ⧟ 𝜑) |