Proof of Theorem ifpnannanb
| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | df-nan 1491 | . . 3
⊢ ((𝜓 ⊼ 𝜒) ↔ ¬ (𝜓 ∧ 𝜒)) | 
| 2 |  | df-nan 1491 | . . 3
⊢ ((𝜃 ⊼ 𝜏) ↔ ¬ (𝜃 ∧ 𝜏)) | 
| 3 |  | ifpbi23 43491 | . . 3
⊢ ((((𝜓 ⊼ 𝜒) ↔ ¬ (𝜓 ∧ 𝜒)) ∧ ((𝜃 ⊼ 𝜏) ↔ ¬ (𝜃 ∧ 𝜏))) → (if-(𝜑, (𝜓 ⊼ 𝜒), (𝜃 ⊼ 𝜏)) ↔ if-(𝜑, ¬ (𝜓 ∧ 𝜒), ¬ (𝜃 ∧ 𝜏)))) | 
| 4 | 1, 2, 3 | mp2an 692 | . 2
⊢
(if-(𝜑, (𝜓 ⊼ 𝜒), (𝜃 ⊼ 𝜏)) ↔ if-(𝜑, ¬ (𝜓 ∧ 𝜒), ¬ (𝜃 ∧ 𝜏))) | 
| 5 |  | ifpananb 43524 | . . . 4
⊢
(if-(𝜑, (𝜓 ∧ 𝜒), (𝜃 ∧ 𝜏)) ↔ (if-(𝜑, 𝜓, 𝜃) ∧ if-(𝜑, 𝜒, 𝜏))) | 
| 6 | 5 | notbii 320 | . . 3
⊢ (¬
if-(𝜑, (𝜓 ∧ 𝜒), (𝜃 ∧ 𝜏)) ↔ ¬ (if-(𝜑, 𝜓, 𝜃) ∧ if-(𝜑, 𝜒, 𝜏))) | 
| 7 |  | ifpnotnotb 43497 | . . 3
⊢
(if-(𝜑, ¬ (𝜓 ∧ 𝜒), ¬ (𝜃 ∧ 𝜏)) ↔ ¬ if-(𝜑, (𝜓 ∧ 𝜒), (𝜃 ∧ 𝜏))) | 
| 8 |  | df-nan 1491 | . . 3
⊢
((if-(𝜑, 𝜓, 𝜃) ⊼ if-(𝜑, 𝜒, 𝜏)) ↔ ¬ (if-(𝜑, 𝜓, 𝜃) ∧ if-(𝜑, 𝜒, 𝜏))) | 
| 9 | 6, 7, 8 | 3bitr4i 303 | . 2
⊢
(if-(𝜑, ¬ (𝜓 ∧ 𝜒), ¬ (𝜃 ∧ 𝜏)) ↔ (if-(𝜑, 𝜓, 𝜃) ⊼ if-(𝜑, 𝜒, 𝜏))) | 
| 10 | 4, 9 | bitri 275 | 1
⊢
(if-(𝜑, (𝜓 ⊼ 𝜒), (𝜃 ⊼ 𝜏)) ↔ (if-(𝜑, 𝜓, 𝜃) ⊼ if-(𝜑, 𝜒, 𝜏))) |