Proof of Theorem ifpid1g
Step | Hyp | Ref
| Expression |
1 | | ifpidg 41060 |
. 2
⊢ ((𝜑 ↔ if-(𝜑, 𝜓, 𝜒)) ↔ ((((𝜑 ∧ 𝜓) → 𝜑) ∧ ((𝜑 ∧ 𝜑) → 𝜓)) ∧ ((𝜒 → (𝜑 ∨ 𝜑)) ∧ (𝜑 → (𝜑 ∨ 𝜒))))) |
2 | | ancom 460 |
. 2
⊢
(((((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 | | pm4.25 902 |
. . . . 5
⊢ (𝜑 ↔ (𝜑 ∨ 𝜑)) |
4 | 3 | imbi2i 335 |
. . . 4
⊢ ((𝜒 → 𝜑) ↔ (𝜒 → (𝜑 ∨ 𝜑))) |
5 | | orc 863 |
. . . . 5
⊢ (𝜑 → (𝜑 ∨ 𝜒)) |
6 | 5 | biantru 529 |
. . . 4
⊢ ((𝜒 → (𝜑 ∨ 𝜑)) ↔ ((𝜒 → (𝜑 ∨ 𝜑)) ∧ (𝜑 → (𝜑 ∨ 𝜒)))) |
7 | 4, 6 | bitr2i 275 |
. . 3
⊢ (((𝜒 → (𝜑 ∨ 𝜑)) ∧ (𝜑 → (𝜑 ∨ 𝜒))) ↔ (𝜒 → 𝜑)) |
8 | | pm4.24 563 |
. . . . 5
⊢ (𝜑 ↔ (𝜑 ∧ 𝜑)) |
9 | 8 | imbi1i 349 |
. . . 4
⊢ ((𝜑 → 𝜓) ↔ ((𝜑 ∧ 𝜑) → 𝜓)) |
10 | | simpl 482 |
. . . . 5
⊢ ((𝜑 ∧ 𝜓) → 𝜑) |
11 | 10 | biantrur 530 |
. . . 4
⊢ (((𝜑 ∧ 𝜑) → 𝜓) ↔ (((𝜑 ∧ 𝜓) → 𝜑) ∧ ((𝜑 ∧ 𝜑) → 𝜓))) |
12 | 9, 11 | bitr2i 275 |
. . 3
⊢ ((((𝜑 ∧ 𝜓) → 𝜑) ∧ ((𝜑 ∧ 𝜑) → 𝜓)) ↔ (𝜑 → 𝜓)) |
13 | 7, 12 | anbi12i 626 |
. 2
⊢ ((((𝜒 → (𝜑 ∨ 𝜑)) ∧ (𝜑 → (𝜑 ∨ 𝜒))) ∧ (((𝜑 ∧ 𝜓) → 𝜑) ∧ ((𝜑 ∧ 𝜑) → 𝜓))) ↔ ((𝜒 → 𝜑) ∧ (𝜑 → 𝜓))) |
14 | 1, 2, 13 | 3bitri 296 |
1
⊢ ((𝜑 ↔ if-(𝜑, 𝜓, 𝜒)) ↔ ((𝜒 → 𝜑) ∧ (𝜑 → 𝜓))) |