Metamath Proof Explorer


Theorem oppcval

Description: Value of the opposite category. (Contributed by Mario Carneiro, 2-Jan-2017)

Ref Expression
Hypotheses oppcval.b ⊢ B = Base C
oppcval.h ⊢ H = Hom ⁡ C
oppcval.x ⊢ · ˙ = comp ⁡ C
oppcval.o ⊢ O = oppCat ⁡ C
Assertion oppcval ⊢ C ∈ V → O = C sSet Hom ⁡ ndx tpos H sSet comp ⁡ ndx u ∈ B × B , z ∈ B ⟼ tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u

Proof

Step Hyp Ref Expression
1 oppcval.b ⊢ B = Base C
2 oppcval.h ⊢ H = Hom ⁡ C
3 oppcval.x ⊢ · ˙ = comp ⁡ C
4 oppcval.o ⊢ O = oppCat ⁡ C
5 elex ⊢ C ∈ V → C ∈ V
6 id ⊢ c = C → c = C
7 fveq2 ⊢ c = C → Hom ⁡ c = Hom ⁡ C
8 7 2 eqtr4di ⊢ c = C → Hom ⁡ c = H
9 8 tposeqd ⊢ c = C → tpos Hom ⁡ c = tpos H
10 9 opeq2d ⊢ c = C → Hom ⁡ ndx tpos Hom ⁡ c = Hom ⁡ ndx tpos H
11 6 10 oveq12d ⊢ c = C → c sSet Hom ⁡ ndx tpos Hom ⁡ c = C sSet Hom ⁡ ndx tpos H
12 fveq2 ⊢ c = C → Base c = Base C
13 12 1 eqtr4di ⊢ c = C → Base c = B
14 13 sqxpeqd ⊢ c = C → Base c × Base c = B × B
15 fveq2 ⊢ c = C → comp ⁡ c = comp ⁡ C
16 15 3 eqtr4di ⊢ c = C → comp ⁡ c = · ˙
17 16 oveqd ⊢ c = C → z 2 nd ⁡ u comp ⁡ c 1 st ⁡ u = z 2 nd ⁡ u · ˙ 1 st ⁡ u
18 17 tposeqd ⊢ c = C → tpos z 2 nd ⁡ u comp ⁡ c 1 st ⁡ u = tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u
19 14 13 18 mpoeq123dv ⊢ c = C → u ∈ Base c × Base c , z ∈ Base c ⟼ tpos z 2 nd ⁡ u comp ⁡ c 1 st ⁡ u = u ∈ B × B , z ∈ B ⟼ tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u
20 19 opeq2d ⊢ c = C → comp ⁡ ndx u ∈ Base c × Base c , z ∈ Base c ⟼ tpos z 2 nd ⁡ u comp ⁡ c 1 st ⁡ u = comp ⁡ ndx u ∈ B × B , z ∈ B ⟼ tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u
21 11 20 oveq12d ⊢ c = C → c sSet Hom ⁡ ndx tpos Hom ⁡ c sSet comp ⁡ ndx u ∈ Base c × Base c , z ∈ Base c ⟼ tpos z 2 nd ⁡ u comp ⁡ c 1 st ⁡ u = C sSet Hom ⁡ ndx tpos H sSet comp ⁡ ndx u ∈ B × B , z ∈ B ⟼ tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u
22 df-oppc ⊢ oppCat = c ∈ V ⟼ c sSet Hom ⁡ ndx tpos Hom ⁡ c sSet comp ⁡ ndx u ∈ Base c × Base c , z ∈ Base c ⟼ tpos z 2 nd ⁡ u comp ⁡ c 1 st ⁡ u
23 ovex ⊢ C sSet Hom ⁡ ndx tpos H sSet comp ⁡ ndx u ∈ B × B , z ∈ B ⟼ tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u ∈ V
24 21 22 23 fvmpt ⊢ C ∈ V → oppCat ⁡ C = C sSet Hom ⁡ ndx tpos H sSet comp ⁡ ndx u ∈ B × B , z ∈ B ⟼ tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u
25 5 24 syl ⊢ C ∈ V → oppCat ⁡ C = C sSet Hom ⁡ ndx tpos H sSet comp ⁡ ndx u ∈ B × B , z ∈ B ⟼ tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u
26 4 25 eqtrid ⊢ C ∈ V → O = C sSet Hom ⁡ ndx tpos H sSet comp ⁡ ndx u ∈ B × B , z ∈ B ⟼ tpos z 2 nd ⁡ u · ˙ 1 st ⁡ u