Proof of Theorem relrelss
Step | Hyp | Ref
| Expression |
1 | | df-rel 4618 |
. . 3
⊢ (Rel dom
𝐴 ↔ dom 𝐴 ⊆ (V ×
V)) |
2 | 1 | anbi2i 454 |
. 2
⊢ ((Rel
𝐴 ∧ Rel dom 𝐴) ↔ (Rel 𝐴 ∧ dom 𝐴 ⊆ (V × V))) |
3 | | relssdmrn 5131 |
. . . 4
⊢ (Rel
𝐴 → 𝐴 ⊆ (dom 𝐴 × ran 𝐴)) |
4 | | ssv 3169 |
. . . . 5
⊢ ran 𝐴 ⊆ V |
5 | | xpss12 4718 |
. . . . 5
⊢ ((dom
𝐴 ⊆ (V × V)
∧ ran 𝐴 ⊆ V)
→ (dom 𝐴 × ran
𝐴) ⊆ ((V × V)
× V)) |
6 | 4, 5 | mpan2 423 |
. . . 4
⊢ (dom
𝐴 ⊆ (V × V)
→ (dom 𝐴 × ran
𝐴) ⊆ ((V × V)
× V)) |
7 | 3, 6 | sylan9ss 3160 |
. . 3
⊢ ((Rel
𝐴 ∧ dom 𝐴 ⊆ (V × V)) →
𝐴 ⊆ ((V × V)
× V)) |
8 | | xpss 4719 |
. . . . . 6
⊢ ((V
× V) × V) ⊆ (V × V) |
9 | | sstr 3155 |
. . . . . 6
⊢ ((𝐴 ⊆ ((V × V) ×
V) ∧ ((V × V) × V) ⊆ (V × V)) → 𝐴 ⊆ (V ×
V)) |
10 | 8, 9 | mpan2 423 |
. . . . 5
⊢ (𝐴 ⊆ ((V × V) ×
V) → 𝐴 ⊆ (V
× V)) |
11 | | df-rel 4618 |
. . . . 5
⊢ (Rel
𝐴 ↔ 𝐴 ⊆ (V × V)) |
12 | 10, 11 | sylibr 133 |
. . . 4
⊢ (𝐴 ⊆ ((V × V) ×
V) → Rel 𝐴) |
13 | | dmss 4810 |
. . . . 5
⊢ (𝐴 ⊆ ((V × V) ×
V) → dom 𝐴 ⊆ dom
((V × V) × V)) |
14 | | vn0m 3426 |
. . . . . 6
⊢
∃𝑥 𝑥 ∈ V |
15 | | dmxpm 4831 |
. . . . . 6
⊢
(∃𝑥 𝑥 ∈ V → dom ((V ×
V) × V) = (V × V)) |
16 | 14, 15 | ax-mp 5 |
. . . . 5
⊢ dom ((V
× V) × V) = (V × V) |
17 | 13, 16 | sseqtrdi 3195 |
. . . 4
⊢ (𝐴 ⊆ ((V × V) ×
V) → dom 𝐴 ⊆ (V
× V)) |
18 | 12, 17 | jca 304 |
. . 3
⊢ (𝐴 ⊆ ((V × V) ×
V) → (Rel 𝐴 ∧ dom
𝐴 ⊆ (V ×
V))) |
19 | 7, 18 | impbii 125 |
. 2
⊢ ((Rel
𝐴 ∧ dom 𝐴 ⊆ (V × V)) ↔
𝐴 ⊆ ((V × V)
× V)) |
20 | 2, 19 | bitri 183 |
1
⊢ ((Rel
𝐴 ∧ Rel dom 𝐴) ↔ 𝐴 ⊆ ((V × V) ×
V)) |