Metamath Proof Explorer
		
		
		
		Description:  A way to say " A is a set" (inference form).  (Contributed by NM, 24-Jun-1993)  Remove dependencies on axioms.  (Revised by BJ, 13-Jul-2019)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypothesis | isseti.1 |  | 
				
					|  | Assertion | isseti |  | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isseti.1 |  | 
						
							| 2 |  | elissetv |  | 
						
							| 3 | 1 2 | ax-mp |  |