| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | df-po 5591 | . . 3
⊢ (𝑅 Po 𝐴 ↔ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (¬ 𝑥𝑅𝑥 ∧ ((𝑥𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝑥𝑅𝑧))) | 
| 2 | 1 | biimpi 216 | . 2
⊢ (𝑅 Po 𝐴 → ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (¬ 𝑥𝑅𝑥 ∧ ((𝑥𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝑥𝑅𝑧))) | 
| 3 |  | id 22 | . . . . . 6
⊢ (𝑥 = 𝐵 → 𝑥 = 𝐵) | 
| 4 | 3, 3 | breq12d 5155 | . . . . 5
⊢ (𝑥 = 𝐵 → (𝑥𝑅𝑥 ↔ 𝐵𝑅𝐵)) | 
| 5 | 4 | notbid 318 | . . . 4
⊢ (𝑥 = 𝐵 → (¬ 𝑥𝑅𝑥 ↔ ¬ 𝐵𝑅𝐵)) | 
| 6 |  | breq1 5145 | . . . . . 6
⊢ (𝑥 = 𝐵 → (𝑥𝑅𝑦 ↔ 𝐵𝑅𝑦)) | 
| 7 | 6 | anbi1d 631 | . . . . 5
⊢ (𝑥 = 𝐵 → ((𝑥𝑅𝑦 ∧ 𝑦𝑅𝑧) ↔ (𝐵𝑅𝑦 ∧ 𝑦𝑅𝑧))) | 
| 8 |  | breq1 5145 | . . . . 5
⊢ (𝑥 = 𝐵 → (𝑥𝑅𝑧 ↔ 𝐵𝑅𝑧)) | 
| 9 | 7, 8 | imbi12d 344 | . . . 4
⊢ (𝑥 = 𝐵 → (((𝑥𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝑥𝑅𝑧) ↔ ((𝐵𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝐵𝑅𝑧))) | 
| 10 | 5, 9 | anbi12d 632 | . . 3
⊢ (𝑥 = 𝐵 → ((¬ 𝑥𝑅𝑥 ∧ ((𝑥𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝑥𝑅𝑧)) ↔ (¬ 𝐵𝑅𝐵 ∧ ((𝐵𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝐵𝑅𝑧)))) | 
| 11 |  | breq2 5146 | . . . . . 6
⊢ (𝑦 = 𝐶 → (𝐵𝑅𝑦 ↔ 𝐵𝑅𝐶)) | 
| 12 |  | breq1 5145 | . . . . . 6
⊢ (𝑦 = 𝐶 → (𝑦𝑅𝑧 ↔ 𝐶𝑅𝑧)) | 
| 13 | 11, 12 | anbi12d 632 | . . . . 5
⊢ (𝑦 = 𝐶 → ((𝐵𝑅𝑦 ∧ 𝑦𝑅𝑧) ↔ (𝐵𝑅𝐶 ∧ 𝐶𝑅𝑧))) | 
| 14 | 13 | imbi1d 341 | . . . 4
⊢ (𝑦 = 𝐶 → (((𝐵𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝐵𝑅𝑧) ↔ ((𝐵𝑅𝐶 ∧ 𝐶𝑅𝑧) → 𝐵𝑅𝑧))) | 
| 15 | 14 | anbi2d 630 | . . 3
⊢ (𝑦 = 𝐶 → ((¬ 𝐵𝑅𝐵 ∧ ((𝐵𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝐵𝑅𝑧)) ↔ (¬ 𝐵𝑅𝐵 ∧ ((𝐵𝑅𝐶 ∧ 𝐶𝑅𝑧) → 𝐵𝑅𝑧)))) | 
| 16 |  | breq2 5146 | . . . . . 6
⊢ (𝑧 = 𝐷 → (𝐶𝑅𝑧 ↔ 𝐶𝑅𝐷)) | 
| 17 | 16 | anbi2d 630 | . . . . 5
⊢ (𝑧 = 𝐷 → ((𝐵𝑅𝐶 ∧ 𝐶𝑅𝑧) ↔ (𝐵𝑅𝐶 ∧ 𝐶𝑅𝐷))) | 
| 18 |  | breq2 5146 | . . . . 5
⊢ (𝑧 = 𝐷 → (𝐵𝑅𝑧 ↔ 𝐵𝑅𝐷)) | 
| 19 | 17, 18 | imbi12d 344 | . . . 4
⊢ (𝑧 = 𝐷 → (((𝐵𝑅𝐶 ∧ 𝐶𝑅𝑧) → 𝐵𝑅𝑧) ↔ ((𝐵𝑅𝐶 ∧ 𝐶𝑅𝐷) → 𝐵𝑅𝐷))) | 
| 20 | 19 | anbi2d 630 | . . 3
⊢ (𝑧 = 𝐷 → ((¬ 𝐵𝑅𝐵 ∧ ((𝐵𝑅𝐶 ∧ 𝐶𝑅𝑧) → 𝐵𝑅𝑧)) ↔ (¬ 𝐵𝑅𝐵 ∧ ((𝐵𝑅𝐶 ∧ 𝐶𝑅𝐷) → 𝐵𝑅𝐷)))) | 
| 21 | 10, 15, 20 | rspc3v 3637 | . 2
⊢ ((𝐵 ∈ 𝐴 ∧ 𝐶 ∈ 𝐴 ∧ 𝐷 ∈ 𝐴) → (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (¬ 𝑥𝑅𝑥 ∧ ((𝑥𝑅𝑦 ∧ 𝑦𝑅𝑧) → 𝑥𝑅𝑧)) → (¬ 𝐵𝑅𝐵 ∧ ((𝐵𝑅𝐶 ∧ 𝐶𝑅𝐷) → 𝐵𝑅𝐷)))) | 
| 22 | 2, 21 | syl5com 31 | 1
⊢ (𝑅 Po 𝐴 → ((𝐵 ∈ 𝐴 ∧ 𝐶 ∈ 𝐴 ∧ 𝐷 ∈ 𝐴) → (¬ 𝐵𝑅𝐵 ∧ ((𝐵𝑅𝐶 ∧ 𝐶𝑅𝐷) → 𝐵𝑅𝐷)))) |