Metamath Proof Explorer
		
		
		
		Description:  The set of atoms is a subset of the base set.  ( atssch analog.)
       (Contributed by NM, 21-Oct-2011)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | atombase.b |  | 
					
						|  |  | atombase.a |  | 
				
					|  | Assertion | atssbase |  | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | atombase.b |  | 
						
							| 2 |  | atombase.a |  | 
						
							| 3 | 1 2 | atbase |  | 
						
							| 4 | 3 | ssriv |  |