| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | relinxp 5824 | . . 3
⊢ Rel
(𝑅 ∩ (𝐵 × 𝐵)) | 
| 2 | 1 | a1i 11 | . 2
⊢ (𝜑 → Rel (𝑅 ∩ (𝐵 × 𝐵))) | 
| 3 |  | simpr 484 | . . . . 5
⊢ ((𝜑 ∧ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) → 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) | 
| 4 |  | brinxp2 5763 | . . . . 5
⊢ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ↔ ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥𝑅𝑦)) | 
| 5 | 3, 4 | sylib 218 | . . . 4
⊢ ((𝜑 ∧ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥𝑅𝑦)) | 
| 6 | 5 | simplrd 770 | . . 3
⊢ ((𝜑 ∧ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) → 𝑦 ∈ 𝐵) | 
| 7 | 5 | simplld 768 | . . 3
⊢ ((𝜑 ∧ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) → 𝑥 ∈ 𝐵) | 
| 8 |  | erinxp.r | . . . . 5
⊢ (𝜑 → 𝑅 Er 𝐴) | 
| 9 | 8 | adantr 480 | . . . 4
⊢ ((𝜑 ∧ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) → 𝑅 Er 𝐴) | 
| 10 | 5 | simprd 495 | . . . 4
⊢ ((𝜑 ∧ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) → 𝑥𝑅𝑦) | 
| 11 | 9, 10 | ersym 8757 | . . 3
⊢ ((𝜑 ∧ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) → 𝑦𝑅𝑥) | 
| 12 |  | brinxp2 5763 | . . 3
⊢ (𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑥 ↔ ((𝑦 ∈ 𝐵 ∧ 𝑥 ∈ 𝐵) ∧ 𝑦𝑅𝑥)) | 
| 13 | 6, 7, 11, 12 | syl21anbrc 1345 | . 2
⊢ ((𝜑 ∧ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦) → 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑥) | 
| 14 | 7 | adantrr 717 | . . 3
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → 𝑥 ∈ 𝐵) | 
| 15 |  | simprr 773 | . . . . 5
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧) | 
| 16 |  | brinxp2 5763 | . . . . 5
⊢ (𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧 ↔ ((𝑦 ∈ 𝐵 ∧ 𝑧 ∈ 𝐵) ∧ 𝑦𝑅𝑧)) | 
| 17 | 15, 16 | sylib 218 | . . . 4
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → ((𝑦 ∈ 𝐵 ∧ 𝑧 ∈ 𝐵) ∧ 𝑦𝑅𝑧)) | 
| 18 | 17 | simplrd 770 | . . 3
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → 𝑧 ∈ 𝐵) | 
| 19 | 8 | adantr 480 | . . . 4
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → 𝑅 Er 𝐴) | 
| 20 | 10 | adantrr 717 | . . . 4
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → 𝑥𝑅𝑦) | 
| 21 | 17 | simprd 495 | . . . 4
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → 𝑦𝑅𝑧) | 
| 22 | 19, 20, 21 | ertrd 8761 | . . 3
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → 𝑥𝑅𝑧) | 
| 23 |  | brinxp2 5763 | . . 3
⊢ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑧 ↔ ((𝑥 ∈ 𝐵 ∧ 𝑧 ∈ 𝐵) ∧ 𝑥𝑅𝑧)) | 
| 24 | 14, 18, 22, 23 | syl21anbrc 1345 | . 2
⊢ ((𝜑 ∧ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑦 ∧ 𝑦(𝑅 ∩ (𝐵 × 𝐵))𝑧)) → 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑧) | 
| 25 | 8 | adantr 480 | . . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐵) → 𝑅 Er 𝐴) | 
| 26 |  | erinxp.a | . . . . . . 7
⊢ (𝜑 → 𝐵 ⊆ 𝐴) | 
| 27 | 26 | sselda 3983 | . . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐵) → 𝑥 ∈ 𝐴) | 
| 28 | 25, 27 | erref 8765 | . . . . 5
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐵) → 𝑥𝑅𝑥) | 
| 29 | 28 | ex 412 | . . . 4
⊢ (𝜑 → (𝑥 ∈ 𝐵 → 𝑥𝑅𝑥)) | 
| 30 | 29 | pm4.71rd 562 | . . 3
⊢ (𝜑 → (𝑥 ∈ 𝐵 ↔ (𝑥𝑅𝑥 ∧ 𝑥 ∈ 𝐵))) | 
| 31 |  | brin 5195 | . . . 4
⊢ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑥 ↔ (𝑥𝑅𝑥 ∧ 𝑥(𝐵 × 𝐵)𝑥)) | 
| 32 |  | brxp 5734 | . . . . . 6
⊢ (𝑥(𝐵 × 𝐵)𝑥 ↔ (𝑥 ∈ 𝐵 ∧ 𝑥 ∈ 𝐵)) | 
| 33 |  | anidm 564 | . . . . . 6
⊢ ((𝑥 ∈ 𝐵 ∧ 𝑥 ∈ 𝐵) ↔ 𝑥 ∈ 𝐵) | 
| 34 | 32, 33 | bitri 275 | . . . . 5
⊢ (𝑥(𝐵 × 𝐵)𝑥 ↔ 𝑥 ∈ 𝐵) | 
| 35 | 34 | anbi2i 623 | . . . 4
⊢ ((𝑥𝑅𝑥 ∧ 𝑥(𝐵 × 𝐵)𝑥) ↔ (𝑥𝑅𝑥 ∧ 𝑥 ∈ 𝐵)) | 
| 36 | 31, 35 | bitri 275 | . . 3
⊢ (𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑥 ↔ (𝑥𝑅𝑥 ∧ 𝑥 ∈ 𝐵)) | 
| 37 | 30, 36 | bitr4di 289 | . 2
⊢ (𝜑 → (𝑥 ∈ 𝐵 ↔ 𝑥(𝑅 ∩ (𝐵 × 𝐵))𝑥)) | 
| 38 | 2, 13, 24, 37 | iserd 8771 | 1
⊢ (𝜑 → (𝑅 ∩ (𝐵 × 𝐵)) Er 𝐵) |