Metamath Proof Explorer
		
		
		
		Description:  A simple graph is an undirected pseudograph.  (Contributed by Alexander
     van der Vekens, 20-Aug-2017)  (Revised by AV, 15-Oct-2020)
		
			
				
					|  |  | Ref | Expression | 
				
					|  | Assertion | usgrupgr |  | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | usgruspgr |  | 
						
							| 2 |  | uspgrupgr |  | 
						
							| 3 | 1 2 | syl |  |