| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | fveq2 6906 | . . . 4
⊢ (𝑓 = 𝐾 → (Base‘𝑓) = (Base‘𝐾)) | 
| 2 |  | fveq2 6906 | . . . . 5
⊢ (𝑓 = 𝐾 → (le‘𝑓) = (le‘𝐾)) | 
| 3 | 2 | sbceq1d 3793 | . . . 4
⊢ (𝑓 = 𝐾 → ([(le‘𝑓) / 𝑟]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ [(le‘𝐾) / 𝑟]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥))) | 
| 4 | 1, 3 | sbceqbid 3795 | . . 3
⊢ (𝑓 = 𝐾 → ([(Base‘𝑓) / 𝑏][(le‘𝑓) / 𝑟]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ [(Base‘𝐾) / 𝑏][(le‘𝐾) / 𝑟]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥))) | 
| 5 |  | fvex 6919 | . . . 4
⊢
(Base‘𝐾)
∈ V | 
| 6 |  | fvex 6919 | . . . 4
⊢
(le‘𝐾) ∈
V | 
| 7 |  | istos.b | . . . . . 6
⊢ 𝐵 = (Base‘𝐾) | 
| 8 |  | eqtr 2760 | . . . . . . . . 9
⊢ ((𝑏 = (Base‘𝐾) ∧ (Base‘𝐾) = 𝐵) → 𝑏 = 𝐵) | 
| 9 |  | istos.l | . . . . . . . . . 10
⊢  ≤ =
(le‘𝐾) | 
| 10 |  | eqtr 2760 | . . . . . . . . . . . . 13
⊢ ((𝑟 = (le‘𝐾) ∧ (le‘𝐾) = ≤ ) → 𝑟 = ≤ ) | 
| 11 |  | breq 5145 | . . . . . . . . . . . . . . . . 17
⊢ (𝑟 = ≤ → (𝑥𝑟𝑦 ↔ 𝑥 ≤ 𝑦)) | 
| 12 |  | breq 5145 | . . . . . . . . . . . . . . . . 17
⊢ (𝑟 = ≤ → (𝑦𝑟𝑥 ↔ 𝑦 ≤ 𝑥)) | 
| 13 | 11, 12 | orbi12d 919 | . . . . . . . . . . . . . . . 16
⊢ (𝑟 = ≤ → ((𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))) | 
| 14 | 13 | 2ralbidv 3221 | . . . . . . . . . . . . . . 15
⊢ (𝑟 = ≤ → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))) | 
| 15 |  | raleq 3323 | . . . . . . . . . . . . . . . 16
⊢ (𝑏 = 𝐵 → (∀𝑦 ∈ 𝑏 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥) ↔ ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))) | 
| 16 | 15 | raleqbi1dv 3338 | . . . . . . . . . . . . . . 15
⊢ (𝑏 = 𝐵 → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))) | 
| 17 | 14, 16 | sylan9bb 509 | . . . . . . . . . . . . . 14
⊢ ((𝑟 = ≤ ∧ 𝑏 = 𝐵) → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))) | 
| 18 | 17 | ex 412 | . . . . . . . . . . . . 13
⊢ (𝑟 = ≤ → (𝑏 = 𝐵 → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥)))) | 
| 19 | 10, 18 | syl 17 | . . . . . . . . . . . 12
⊢ ((𝑟 = (le‘𝐾) ∧ (le‘𝐾) = ≤ ) → (𝑏 = 𝐵 → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥)))) | 
| 20 | 19 | expcom 413 | . . . . . . . . . . 11
⊢
((le‘𝐾) =
≤
→ (𝑟 = (le‘𝐾) → (𝑏 = 𝐵 → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))))) | 
| 21 | 20 | eqcoms 2745 | . . . . . . . . . 10
⊢ ( ≤ =
(le‘𝐾) → (𝑟 = (le‘𝐾) → (𝑏 = 𝐵 → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))))) | 
| 22 | 9, 21 | ax-mp 5 | . . . . . . . . 9
⊢ (𝑟 = (le‘𝐾) → (𝑏 = 𝐵 → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥)))) | 
| 23 | 8, 22 | syl5com 31 | . . . . . . . 8
⊢ ((𝑏 = (Base‘𝐾) ∧ (Base‘𝐾) = 𝐵) → (𝑟 = (le‘𝐾) → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥)))) | 
| 24 | 23 | expcom 413 | . . . . . . 7
⊢
((Base‘𝐾) =
𝐵 → (𝑏 = (Base‘𝐾) → (𝑟 = (le‘𝐾) → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))))) | 
| 25 | 24 | eqcoms 2745 | . . . . . 6
⊢ (𝐵 = (Base‘𝐾) → (𝑏 = (Base‘𝐾) → (𝑟 = (le‘𝐾) → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))))) | 
| 26 | 7, 25 | ax-mp 5 | . . . . 5
⊢ (𝑏 = (Base‘𝐾) → (𝑟 = (le‘𝐾) → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥)))) | 
| 27 | 26 | imp 406 | . . . 4
⊢ ((𝑏 = (Base‘𝐾) ∧ 𝑟 = (le‘𝐾)) → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))) | 
| 28 | 5, 6, 27 | sbc2ie 3866 | . . 3
⊢
([(Base‘𝐾) / 𝑏][(le‘𝐾) / 𝑟]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥)) | 
| 29 | 4, 28 | bitrdi 287 | . 2
⊢ (𝑓 = 𝐾 → ([(Base‘𝑓) / 𝑏][(le‘𝑓) / 𝑟]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))) | 
| 30 |  | df-toset 18462 | . 2
⊢ Toset =
{𝑓 ∈ Poset ∣
[(Base‘𝑓) /
𝑏][(le‘𝑓) / 𝑟]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥𝑟𝑦 ∨ 𝑦𝑟𝑥)} | 
| 31 | 29, 30 | elrab2 3695 | 1
⊢ (𝐾 ∈ Toset ↔ (𝐾 ∈ Poset ∧
∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ≤ 𝑦 ∨ 𝑦 ≤ 𝑥))) |