Metamath Proof Explorer


Theorem rusgrprc

Description: The class of 0-regular simple graphs is a proper class. (Contributed by AV, 27-Dec-2020)

Ref Expression
Assertion rusgrprc g | g RegUSGraph 0 V

Proof

Step Hyp Ref Expression
1 rgrusgrprc g USGraph | v Vtx g VtxDeg g v = 0 V
2 vex g V
3 0xnn0 0 0 *
4 eqid Vtx g = Vtx g
5 eqid VtxDeg g = VtxDeg g
6 4 5 isrusgr0 g V 0 0 * g RegUSGraph 0 g USGraph 0 0 * v Vtx g VtxDeg g v = 0
7 2 3 6 mp2an g RegUSGraph 0 g USGraph 0 0 * v Vtx g VtxDeg g v = 0
8 3ancomb g USGraph 0 0 * v Vtx g VtxDeg g v = 0 g USGraph v Vtx g VtxDeg g v = 0 0 0 *
9 df-3an g USGraph v Vtx g VtxDeg g v = 0 0 0 * g USGraph v Vtx g VtxDeg g v = 0 0 0 *
10 3 9 mpbiran2 g USGraph v Vtx g VtxDeg g v = 0 0 0 * g USGraph v Vtx g VtxDeg g v = 0
11 7 8 10 3bitri g RegUSGraph 0 g USGraph v Vtx g VtxDeg g v = 0
12 11 abbii g | g RegUSGraph 0 = g | g USGraph v Vtx g VtxDeg g v = 0
13 df-rab g USGraph | v Vtx g VtxDeg g v = 0 = g | g USGraph v Vtx g VtxDeg g v = 0
14 12 13 eqtr4i g | g RegUSGraph 0 = g USGraph | v Vtx g VtxDeg g v = 0
15 neleq1 g | g RegUSGraph 0 = g USGraph | v Vtx g VtxDeg g v = 0 g | g RegUSGraph 0 V g USGraph | v Vtx g VtxDeg g v = 0 V
16 14 15 ax-mp g | g RegUSGraph 0 V g USGraph | v Vtx g VtxDeg g v = 0 V
17 1 16 mpbir g | g RegUSGraph 0 V