Metamath Proof Explorer


Theorem isprs

Description: Property of being a preordered set. (Contributed by Stefan O'Rear, 31-Jan-2015)

Ref Expression
Hypotheses isprs.b ⊢ B = Base K
isprs.l ⊢ ≤ ˙ = ≤ K
Assertion isprs ⊢ K ∈ Proset ↔ K ∈ V ∧ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z

Proof

Step Hyp Ref Expression
1 isprs.b ⊢ B = Base K
2 isprs.l ⊢ ≤ ˙ = ≤ K
3 fveq2 ⊢ f = K → Base f = Base K
4 fveq2 ⊢ f = K → ≤ f = ≤ K
5 4 sbceq1d ⊢ f = K → [˙≤ f / r]˙ ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ [˙≤ K / r]˙ ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z
6 3 5 sbceqbid ⊢ f = K → [˙Base f / b]˙ [˙≤ f / r]˙ ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ [˙Base K / b]˙ [˙≤ K / r]˙ ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z
7 fvex ⊢ Base K ∈ V
8 fvex ⊢ ≤ K ∈ V
9 eqtr3 ⊢ b = Base K ∧ B = Base K → b = B
10 1 9 mpan2 ⊢ b = Base K → b = B
11 raleq ⊢ b = B → ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ ∀ z ∈ B x r x ∧ x r y ∧ y r z → x r z
12 11 raleqbi1dv ⊢ b = B → ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ ∀ y ∈ B ∀ z ∈ B x r x ∧ x r y ∧ y r z → x r z
13 12 raleqbi1dv ⊢ b = B → ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x r x ∧ x r y ∧ y r z → x r z
14 10 13 syl ⊢ b = Base K → ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x r x ∧ x r y ∧ y r z → x r z
15 eqtr3 ⊢ r = ≤ K ∧ ≤ ˙ = ≤ K → r = ≤ ˙
16 2 15 mpan2 ⊢ r = ≤ K → r = ≤ ˙
17 breq ⊢ r = ≤ ˙ → x r x ↔ x ≤ ˙ x
18 breq ⊢ r = ≤ ˙ → x r y ↔ x ≤ ˙ y
19 breq ⊢ r = ≤ ˙ → y r z ↔ y ≤ ˙ z
20 18 19 anbi12d ⊢ r = ≤ ˙ → x r y ∧ y r z ↔ x ≤ ˙ y ∧ y ≤ ˙ z
21 breq ⊢ r = ≤ ˙ → x r z ↔ x ≤ ˙ z
22 20 21 imbi12d ⊢ r = ≤ ˙ → x r y ∧ y r z → x r z ↔ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z
23 17 22 anbi12d ⊢ r = ≤ ˙ → x r x ∧ x r y ∧ y r z → x r z ↔ x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z
24 23 ralbidv ⊢ r = ≤ ˙ → ∀ z ∈ B x r x ∧ x r y ∧ y r z → x r z ↔ ∀ z ∈ B x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z
25 24 2ralbidv ⊢ r = ≤ ˙ → ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x r x ∧ x r y ∧ y r z → x r z ↔ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z
26 16 25 syl ⊢ r = ≤ K → ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x r x ∧ x r y ∧ y r z → x r z ↔ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z
27 14 26 sylan9bb ⊢ b = Base K ∧ r = ≤ K → ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z
28 7 8 27 sbc2ie ⊢ [˙Base K / b]˙ [˙≤ K / r]˙ ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z
29 6 28 bitrdi ⊢ f = K → [˙Base f / b]˙ [˙≤ f / r]˙ ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z ↔ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z
30 df-proset ⊢ Proset = f | [˙Base f / b]˙ [˙≤ f / r]˙ ∀ x ∈ b ∀ y ∈ b ∀ z ∈ b x r x ∧ x r y ∧ y r z → x r z
31 29 30 elab4g ⊢ K ∈ Proset ↔ K ∈ V ∧ ∀ x ∈ B ∀ y ∈ B ∀ z ∈ B x ≤ ˙ x ∧ x ≤ ˙ y ∧ y ≤ ˙ z → x ≤ ˙ z