| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | tospos 18466 | . . 3
⊢ (𝐹 ∈ Toset → 𝐹 ∈ Poset) | 
| 2 |  | resspos 32957 | . . 3
⊢ ((𝐹 ∈ Poset ∧ 𝐴 ∈ 𝑉) → (𝐹 ↾s 𝐴) ∈ Poset) | 
| 3 | 1, 2 | sylan 580 | . 2
⊢ ((𝐹 ∈ Toset ∧ 𝐴 ∈ 𝑉) → (𝐹 ↾s 𝐴) ∈ Poset) | 
| 4 |  | eqid 2736 | . . . . . . 7
⊢ (𝐹 ↾s 𝐴) = (𝐹 ↾s 𝐴) | 
| 5 |  | eqid 2736 | . . . . . . 7
⊢
(Base‘𝐹) =
(Base‘𝐹) | 
| 6 | 4, 5 | ressbas 17281 | . . . . . 6
⊢ (𝐴 ∈ 𝑉 → (𝐴 ∩ (Base‘𝐹)) = (Base‘(𝐹 ↾s 𝐴))) | 
| 7 |  | inss2 4237 | . . . . . 6
⊢ (𝐴 ∩ (Base‘𝐹)) ⊆ (Base‘𝐹) | 
| 8 | 6, 7 | eqsstrrdi 4028 | . . . . 5
⊢ (𝐴 ∈ 𝑉 → (Base‘(𝐹 ↾s 𝐴)) ⊆ (Base‘𝐹)) | 
| 9 | 8 | adantl 481 | . . . 4
⊢ ((𝐹 ∈ Toset ∧ 𝐴 ∈ 𝑉) → (Base‘(𝐹 ↾s 𝐴)) ⊆ (Base‘𝐹)) | 
| 10 |  | eqid 2736 | . . . . . . 7
⊢
(le‘𝐹) =
(le‘𝐹) | 
| 11 | 5, 10 | istos 18464 | . . . . . 6
⊢ (𝐹 ∈ Toset ↔ (𝐹 ∈ Poset ∧
∀𝑥 ∈
(Base‘𝐹)∀𝑦 ∈ (Base‘𝐹)(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥))) | 
| 12 | 11 | simprbi 496 | . . . . 5
⊢ (𝐹 ∈ Toset →
∀𝑥 ∈
(Base‘𝐹)∀𝑦 ∈ (Base‘𝐹)(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥)) | 
| 13 | 12 | adantr 480 | . . . 4
⊢ ((𝐹 ∈ Toset ∧ 𝐴 ∈ 𝑉) → ∀𝑥 ∈ (Base‘𝐹)∀𝑦 ∈ (Base‘𝐹)(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥)) | 
| 14 |  | ssralv 4051 | . . . . 5
⊢
((Base‘(𝐹
↾s 𝐴))
⊆ (Base‘𝐹)
→ (∀𝑥 ∈
(Base‘𝐹)∀𝑦 ∈ (Base‘𝐹)(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥) → ∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘𝐹)(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥))) | 
| 15 |  | ssralv 4051 | . . . . . 6
⊢
((Base‘(𝐹
↾s 𝐴))
⊆ (Base‘𝐹)
→ (∀𝑦 ∈
(Base‘𝐹)(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥) → ∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥))) | 
| 16 | 15 | ralimdv 3168 | . . . . 5
⊢
((Base‘(𝐹
↾s 𝐴))
⊆ (Base‘𝐹)
→ (∀𝑥 ∈
(Base‘(𝐹
↾s 𝐴))∀𝑦 ∈ (Base‘𝐹)(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥) → ∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥))) | 
| 17 | 14, 16 | syld 47 | . . . 4
⊢
((Base‘(𝐹
↾s 𝐴))
⊆ (Base‘𝐹)
→ (∀𝑥 ∈
(Base‘𝐹)∀𝑦 ∈ (Base‘𝐹)(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥) → ∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥))) | 
| 18 | 9, 13, 17 | sylc 65 | . . 3
⊢ ((𝐹 ∈ Toset ∧ 𝐴 ∈ 𝑉) → ∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥)) | 
| 19 | 4, 10 | ressle 17425 | . . . . . . 7
⊢ (𝐴 ∈ 𝑉 → (le‘𝐹) = (le‘(𝐹 ↾s 𝐴))) | 
| 20 | 19 | breqd 5153 | . . . . . 6
⊢ (𝐴 ∈ 𝑉 → (𝑥(le‘𝐹)𝑦 ↔ 𝑥(le‘(𝐹 ↾s 𝐴))𝑦)) | 
| 21 | 19 | breqd 5153 | . . . . . 6
⊢ (𝐴 ∈ 𝑉 → (𝑦(le‘𝐹)𝑥 ↔ 𝑦(le‘(𝐹 ↾s 𝐴))𝑥)) | 
| 22 | 20, 21 | orbi12d 918 | . . . . 5
⊢ (𝐴 ∈ 𝑉 → ((𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥) ↔ (𝑥(le‘(𝐹 ↾s 𝐴))𝑦 ∨ 𝑦(le‘(𝐹 ↾s 𝐴))𝑥))) | 
| 23 | 22 | 2ralbidv 3220 | . . . 4
⊢ (𝐴 ∈ 𝑉 → (∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥) ↔ ∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘(𝐹 ↾s 𝐴))𝑦 ∨ 𝑦(le‘(𝐹 ↾s 𝐴))𝑥))) | 
| 24 | 23 | adantl 481 | . . 3
⊢ ((𝐹 ∈ Toset ∧ 𝐴 ∈ 𝑉) → (∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘𝐹)𝑦 ∨ 𝑦(le‘𝐹)𝑥) ↔ ∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘(𝐹 ↾s 𝐴))𝑦 ∨ 𝑦(le‘(𝐹 ↾s 𝐴))𝑥))) | 
| 25 | 18, 24 | mpbid 232 | . 2
⊢ ((𝐹 ∈ Toset ∧ 𝐴 ∈ 𝑉) → ∀𝑥 ∈ (Base‘(𝐹 ↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘(𝐹 ↾s 𝐴))𝑦 ∨ 𝑦(le‘(𝐹 ↾s 𝐴))𝑥)) | 
| 26 |  | eqid 2736 | . . 3
⊢
(Base‘(𝐹
↾s 𝐴)) =
(Base‘(𝐹
↾s 𝐴)) | 
| 27 |  | eqid 2736 | . . 3
⊢
(le‘(𝐹
↾s 𝐴)) =
(le‘(𝐹
↾s 𝐴)) | 
| 28 | 26, 27 | istos 18464 | . 2
⊢ ((𝐹 ↾s 𝐴) ∈ Toset ↔ ((𝐹 ↾s 𝐴) ∈ Poset ∧
∀𝑥 ∈
(Base‘(𝐹
↾s 𝐴))∀𝑦 ∈ (Base‘(𝐹 ↾s 𝐴))(𝑥(le‘(𝐹 ↾s 𝐴))𝑦 ∨ 𝑦(le‘(𝐹 ↾s 𝐴))𝑥))) | 
| 29 | 3, 25, 28 | sylanbrc 583 | 1
⊢ ((𝐹 ∈ Toset ∧ 𝐴 ∈ 𝑉) → (𝐹 ↾s 𝐴) ∈ Toset) |