Metamath Proof Explorer


Definition df-ringc

Description: Definition of the category Ring, relativized to a subset u . See also the note in Lang p. 91, and the item Rng in Adamek p. 478. This is the category of all unital rings in u and homomorphisms between these rings. 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 AV, 13-Feb-2020) (Revised by AV, 8-Mar-2020)

Ref Expression
Assertion df-ringc RingCat=uVExtStrCatucatRingHomuRing×uRing

Detailed syntax breakdown

Step Hyp Ref Expression
0 cringc classRingCat
1 vu setvaru
2 cvv classV
3 cestrc classExtStrCat
4 1 cv setvaru
5 4 3 cfv classExtStrCatu
6 cresc classcat
7 crh classRingHom
8 crg classRing
9 4 8 cin classuRing
10 9 9 cxp classuRing×uRing
11 7 10 cres classRingHomuRing×uRing
12 5 11 6 co classExtStrCatucatRingHomuRing×uRing
13 1 2 12 cmpt classuVExtStrCatucatRingHomuRing×uRing
14 0 13 wceq wffRingCat=uVExtStrCatucatRingHomuRing×uRing