Step |
Hyp |
Ref |
Expression |
1 |
|
ifpidg |
⊢ ( ( 𝜑 ↔ if- ( 𝜑 , 𝜓 , 𝜒 ) ) ↔ ( ( ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) ∧ ( ( 𝜑 ∧ 𝜑 ) → 𝜓 ) ) ∧ ( ( 𝜒 → ( 𝜑 ∨ 𝜑 ) ) ∧ ( 𝜑 → ( 𝜑 ∨ 𝜒 ) ) ) ) ) |
2 |
|
ancom |
⊢ ( ( ( ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) ∧ ( ( 𝜑 ∧ 𝜑 ) → 𝜓 ) ) ∧ ( ( 𝜒 → ( 𝜑 ∨ 𝜑 ) ) ∧ ( 𝜑 → ( 𝜑 ∨ 𝜒 ) ) ) ) ↔ ( ( ( 𝜒 → ( 𝜑 ∨ 𝜑 ) ) ∧ ( 𝜑 → ( 𝜑 ∨ 𝜒 ) ) ) ∧ ( ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) ∧ ( ( 𝜑 ∧ 𝜑 ) → 𝜓 ) ) ) ) |
3 |
|
pm4.25 |
⊢ ( 𝜑 ↔ ( 𝜑 ∨ 𝜑 ) ) |
4 |
3
|
imbi2i |
⊢ ( ( 𝜒 → 𝜑 ) ↔ ( 𝜒 → ( 𝜑 ∨ 𝜑 ) ) ) |
5 |
|
orc |
⊢ ( 𝜑 → ( 𝜑 ∨ 𝜒 ) ) |
6 |
5
|
biantru |
⊢ ( ( 𝜒 → ( 𝜑 ∨ 𝜑 ) ) ↔ ( ( 𝜒 → ( 𝜑 ∨ 𝜑 ) ) ∧ ( 𝜑 → ( 𝜑 ∨ 𝜒 ) ) ) ) |
7 |
4 6
|
bitr2i |
⊢ ( ( ( 𝜒 → ( 𝜑 ∨ 𝜑 ) ) ∧ ( 𝜑 → ( 𝜑 ∨ 𝜒 ) ) ) ↔ ( 𝜒 → 𝜑 ) ) |
8 |
|
pm4.24 |
⊢ ( 𝜑 ↔ ( 𝜑 ∧ 𝜑 ) ) |
9 |
8
|
imbi1i |
⊢ ( ( 𝜑 → 𝜓 ) ↔ ( ( 𝜑 ∧ 𝜑 ) → 𝜓 ) ) |
10 |
|
simpl |
⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) |
11 |
10
|
biantrur |
⊢ ( ( ( 𝜑 ∧ 𝜑 ) → 𝜓 ) ↔ ( ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) ∧ ( ( 𝜑 ∧ 𝜑 ) → 𝜓 ) ) ) |
12 |
9 11
|
bitr2i |
⊢ ( ( ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) ∧ ( ( 𝜑 ∧ 𝜑 ) → 𝜓 ) ) ↔ ( 𝜑 → 𝜓 ) ) |
13 |
7 12
|
anbi12i |
⊢ ( ( ( ( 𝜒 → ( 𝜑 ∨ 𝜑 ) ) ∧ ( 𝜑 → ( 𝜑 ∨ 𝜒 ) ) ) ∧ ( ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) ∧ ( ( 𝜑 ∧ 𝜑 ) → 𝜓 ) ) ) ↔ ( ( 𝜒 → 𝜑 ) ∧ ( 𝜑 → 𝜓 ) ) ) |
14 |
1 2 13
|
3bitri |
⊢ ( ( 𝜑 ↔ if- ( 𝜑 , 𝜓 , 𝜒 ) ) ↔ ( ( 𝜒 → 𝜑 ) ∧ ( 𝜑 → 𝜓 ) ) ) |