Metamath Proof Explorer
		
		
		
		Description:  Define the class of all singletons.  See elsingles for membership.
     (Contributed by Scott Fenton, 19-Feb-2013)
		
			
				
					|  |  | Ref | Expression | 
				
					|  | Assertion | df-singles |  | 
			
		
		
			
				Detailed syntax breakdown
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 0 |  | csingles |  | 
						
							| 1 |  | csingle |  | 
						
							| 2 | 1 | crn |  | 
						
							| 3 | 0 2 | wceq |  |