Description: The class of simple graphs is a proper class (and therefore, because of prcssprc , the classes of multigraphs, pseudographs and hypergraphs are proper classes, too). (Contributed by AV, 27-Dec-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | usgrprc | |- USGraph e/ _V  | 
				
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqid |  |-  { <. v , e >. | e : (/) --> (/) } = { <. v , e >. | e : (/) --> (/) } | 
						|
| 2 | 1 | griedg0ssusgr |  |-  { <. v , e >. | e : (/) --> (/) } C_ USGraph | 
						
| 3 | 1 | griedg0prc |  |-  { <. v , e >. | e : (/) --> (/) } e/ _V | 
						
| 4 | prcssprc |  |-  ( ( { <. v , e >. | e : (/) --> (/) } C_ USGraph /\ { <. v , e >. | e : (/) --> (/) } e/ _V ) -> USGraph e/ _V ) | 
						|
| 5 | 2 3 4 | mp2an | |- USGraph e/ _V  |