Metamath Proof Explorer


Definition df-setc

Description: Definition of the category Set, relativized to a subset u . Example 3.3(1) of Adamek p. 22. This is the category of all sets in u and functions between these sets. Generally, we will take u to be a weak universe or Grothendieck universe, because these sets have closure properties as good as the real thing. (Contributed by FL, 8-Nov-2013) (Revised by Mario Carneiro, 3-Jan-2017)

Ref Expression
Assertion df-setc ⊢ SetCat = u ∈ V ⟼ Base ndx u Hom ⁡ ndx x ∈ u , y ∈ u ⟼ y x comp ⁡ ndx v ∈ u × u , z ∈ u ⟼ g ∈ z 2 nd ⁡ v , f ∈ 2 nd ⁡ v 1 st ⁡ v ⟼ g ∘ f

Detailed syntax breakdown

Step Hyp Ref Expression
0 csetc class SetCat
1 vu setvar u
2 cvv class V
3 cbs class Base
4 cnx class ndx
5 4 3 cfv class Base ndx
6 1 cv setvar u
7 5 6 cop class Base ndx u
8 chom class Hom
9 4 8 cfv class Hom ⁡ ndx
10 vx setvar x
11 vy setvar y
12 11 cv setvar y
13 cmap class ↑ 𝑚
14 10 cv setvar x
15 12 14 13 co class y x
16 10 11 6 6 15 cmpo class x ∈ u , y ∈ u ⟼ y x
17 9 16 cop class Hom ⁡ ndx x ∈ u , y ∈ u ⟼ y x
18 cco class comp
19 4 18 cfv class comp ⁡ ndx
20 vv setvar v
21 6 6 cxp class u × u
22 vz setvar z
23 vg setvar g
24 22 cv setvar z
25 c2nd class 2 nd
26 20 cv setvar v
27 26 25 cfv class 2 nd ⁡ v
28 24 27 13 co class z 2 nd ⁡ v
29 vf setvar f
30 c1st class 1 st
31 26 30 cfv class 1 st ⁡ v
32 27 31 13 co class 2 nd ⁡ v 1 st ⁡ v
33 23 cv setvar g
34 29 cv setvar f
35 33 34 ccom class g ∘ f
36 23 29 28 32 35 cmpo class g ∈ z 2 nd ⁡ v , f ∈ 2 nd ⁡ v 1 st ⁡ v ⟼ g ∘ f
37 20 22 21 6 36 cmpo class v ∈ u × u , z ∈ u ⟼ g ∈ z 2 nd ⁡ v , f ∈ 2 nd ⁡ v 1 st ⁡ v ⟼ g ∘ f
38 19 37 cop class comp ⁡ ndx v ∈ u × u , z ∈ u ⟼ g ∈ z 2 nd ⁡ v , f ∈ 2 nd ⁡ v 1 st ⁡ v ⟼ g ∘ f
39 7 17 38 ctp class Base ndx u Hom ⁡ ndx x ∈ u , y ∈ u ⟼ y x comp ⁡ ndx v ∈ u × u , z ∈ u ⟼ g ∈ z 2 nd ⁡ v , f ∈ 2 nd ⁡ v 1 st ⁡ v ⟼ g ∘ f
40 1 2 39 cmpt class u ∈ V ⟼ Base ndx u Hom ⁡ ndx x ∈ u , y ∈ u ⟼ y x comp ⁡ ndx v ∈ u × u , z ∈ u ⟼ g ∈ z 2 nd ⁡ v , f ∈ 2 nd ⁡ v 1 st ⁡ v ⟼ g ∘ f
41 0 40 wceq wff SetCat = u ∈ V ⟼ Base ndx u Hom ⁡ ndx x ∈ u , y ∈ u ⟼ y x comp ⁡ ndx v ∈ u × u , z ∈ u ⟼ g ∈ z 2 nd ⁡ v , f ∈ 2 nd ⁡ v 1 st ⁡ v ⟼ g ∘ f