Metamath Proof Explorer


Definition df-rusgr

Description: Define the "k-regular simple graph" predicate, which is true for a simple graph being k-regular: read G RegUSGraph K as G is a K-regular simple graph. (Contributed by Alexander van der Vekens, 6-Jul-2018) (Revised by AV, 18-Dec-2020)

Ref Expression
Assertion df-rusgr
|- RegUSGraph = { <. g , k >. | ( g e. USGraph /\ g RegGraph k ) }

Detailed syntax breakdown

Step Hyp Ref Expression
0 crusgr
 |-  RegUSGraph
1 vg
 |-  g
2 vk
 |-  k
3 1 cv
 |-  g
4 cusgr
 |-  USGraph
5 3 4 wcel
 |-  g e. USGraph
6 crgr
 |-  RegGraph
7 2 cv
 |-  k
8 3 7 6 wbr
 |-  g RegGraph k
9 5 8 wa
 |-  ( g e. USGraph /\ g RegGraph k )
10 9 1 2 copab
 |-  { <. g , k >. | ( g e. USGraph /\ g RegGraph k ) }
11 0 10 wceq
 |-  RegUSGraph = { <. g , k >. | ( g e. USGraph /\ g RegGraph k ) }