Proof of Theorem relssresb
| Step | Hyp | Ref
| Expression |
| 1 | | relssdmrnb 38187 |
. . . 4
⊢ (Rel
𝐴 ↔ 𝐴 ⊆ (dom 𝐴 × ran 𝐴)) |
| 2 | | simpl 488 |
. . . . 5
⊢ ((𝐴 ⊆ (dom 𝐴 × ran 𝐴) ∧ dom 𝐴 ⊆ 𝐵) → 𝐴 ⊆ (dom 𝐴 × ran 𝐴)) |
| 3 | | simpr 490 |
. . . . . 6
⊢ ((𝐴 ⊆ (dom 𝐴 × ran 𝐴) ∧ dom 𝐴 ⊆ 𝐵) → dom 𝐴 ⊆ 𝐵) |
| 4 | | ssv 3937 |
. . . . . 6
⊢ ran 𝐴 ⊆ V |
| 5 | | xpss12 5671 |
. . . . . 6
⊢ ((dom
𝐴 ⊆ 𝐵 ∧ ran 𝐴 ⊆ V) → (dom 𝐴 × ran 𝐴) ⊆ (𝐵 × V)) |
| 6 | 3, 4, 5 | sylancl 598 |
. . . . 5
⊢ ((𝐴 ⊆ (dom 𝐴 × ran 𝐴) ∧ dom 𝐴 ⊆ 𝐵) → (dom 𝐴 × ran 𝐴) ⊆ (𝐵 × V)) |
| 7 | 2, 6 | sstrd 3923 |
. . . 4
⊢ ((𝐴 ⊆ (dom 𝐴 × ran 𝐴) ∧ dom 𝐴 ⊆ 𝐵) → 𝐴 ⊆ (𝐵 × V)) |
| 8 | 1, 7 | sylanb 593 |
. . 3
⊢ ((Rel
𝐴 ∧ dom 𝐴 ⊆ 𝐵) → 𝐴 ⊆ (𝐵 × V)) |
| 9 | | id 23 |
. . . . . 6
⊢ (𝐴 ⊆ (𝐵 × V) → 𝐴 ⊆ (𝐵 × V)) |
| 10 | | xpss 5672 |
. . . . . 6
⊢ (𝐵 × V) ⊆ (V ×
V) |
| 11 | 9, 10 | sstrdi 3925 |
. . . . 5
⊢ (𝐴 ⊆ (𝐵 × V) → 𝐴 ⊆ (V × V)) |
| 12 | | df-rel 5663 |
. . . . 5
⊢ (Rel
𝐴 ↔ 𝐴 ⊆ (V × V)) |
| 13 | 11, 12 | sylibr 237 |
. . . 4
⊢ (𝐴 ⊆ (𝐵 × V) → Rel 𝐴) |
| 14 | | dmss 5894 |
. . . . 5
⊢ (𝐴 ⊆ (𝐵 × V) → dom 𝐴 ⊆ dom (𝐵 × V)) |
| 15 | | dmxpss 6179 |
. . . . 5
⊢ dom
(𝐵 × V) ⊆ 𝐵 |
| 16 | 14, 15 | sstrdi 3925 |
. . . 4
⊢ (𝐴 ⊆ (𝐵 × V) → dom 𝐴 ⊆ 𝐵) |
| 17 | 13, 16 | jca 521 |
. . 3
⊢ (𝐴 ⊆ (𝐵 × V) → (Rel 𝐴 ∧ dom 𝐴 ⊆ 𝐵)) |
| 18 | 8, 17 | impbii 212 |
. 2
⊢ ((Rel
𝐴 ∧ dom 𝐴 ⊆ 𝐵) ↔ 𝐴 ⊆ (𝐵 × V)) |
| 19 | | bj-resssxp 38176 |
. 2
⊢ ((𝐴 ↾ 𝐵) = 𝐴 ↔ 𝐴 ⊆ (𝐵 × V)) |
| 20 | 18, 19 | bitr4i 281 |
1
⊢ ((Rel
𝐴 ∧ dom 𝐴 ⊆ 𝐵) ↔ (𝐴 ↾ 𝐵) = 𝐴) |