Proof of Theorem nic-luk3
| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | nic-dfim 1669 | . . . 4
⊢ (((¬
𝜑 ⊼ (𝜓 ⊼ 𝜓)) ⊼ (¬ 𝜑 → 𝜓)) ⊼ (((¬ 𝜑 ⊼ (𝜓 ⊼ 𝜓)) ⊼ (¬ 𝜑 ⊼ (𝜓 ⊼ 𝜓))) ⊼ ((¬ 𝜑 → 𝜓) ⊼ (¬ 𝜑 → 𝜓)))) | 
| 2 | 1 | nic-bi1 1688 | . . 3
⊢ ((¬
𝜑 ⊼ (𝜓 ⊼ 𝜓)) ⊼ ((¬ 𝜑 → 𝜓) ⊼ (¬ 𝜑 → 𝜓))) | 
| 3 |  | nic-dfneg 1670 | . . . . 5
⊢ (((𝜑 ⊼ 𝜑) ⊼ ¬ 𝜑) ⊼ (((𝜑 ⊼ 𝜑) ⊼ (𝜑 ⊼ 𝜑)) ⊼ (¬ 𝜑 ⊼ ¬ 𝜑))) | 
| 4 | 3 | nic-bi2 1689 | . . . 4
⊢ (¬
𝜑 ⊼ ((𝜑 ⊼ 𝜑) ⊼ (𝜑 ⊼ 𝜑))) | 
| 5 |  | nic-id 1678 | . . . 4
⊢ (𝜑 ⊼ (𝜑 ⊼ 𝜑)) | 
| 6 | 4, 5 | nic-iimp1 1682 | . . 3
⊢ (𝜑 ⊼ ¬ 𝜑) | 
| 7 | 2, 6 | nic-iimp2 1683 | . 2
⊢ (𝜑 ⊼ ((¬ 𝜑 → 𝜓) ⊼ (¬ 𝜑 → 𝜓))) | 
| 8 |  | nic-dfim 1669 | . . 3
⊢ (((𝜑 ⊼ ((¬ 𝜑 → 𝜓) ⊼ (¬ 𝜑 → 𝜓))) ⊼ (𝜑 → (¬ 𝜑 → 𝜓))) ⊼ (((𝜑 ⊼ ((¬ 𝜑 → 𝜓) ⊼ (¬ 𝜑 → 𝜓))) ⊼ (𝜑 ⊼ ((¬ 𝜑 → 𝜓) ⊼ (¬ 𝜑 → 𝜓)))) ⊼ ((𝜑 → (¬ 𝜑 → 𝜓)) ⊼ (𝜑 → (¬ 𝜑 → 𝜓))))) | 
| 9 | 8 | nic-bi1 1688 | . 2
⊢ ((𝜑 ⊼ ((¬ 𝜑 → 𝜓) ⊼ (¬ 𝜑 → 𝜓))) ⊼ ((𝜑 → (¬ 𝜑 → 𝜓)) ⊼ (𝜑 → (¬ 𝜑 → 𝜓)))) | 
| 10 | 7, 9 | nic-mp 1671 | 1
⊢ (𝜑 → (¬ 𝜑 → 𝜓)) |