Metamath Proof Explorer
		
		
		Theorem zex
		Description:  The set of integers exists.  See also zexALT .  (Contributed by NM, 30-Jul-2004)  (Revised by Mario Carneiro, 17-Nov-2014)
		
			
				
					 | 
					 | 
					Ref | 
					Expression | 
				
				
					 | 
					Assertion | 
					zex | 
					   | 
				
			
		
		
			
				Proof
				
					
						| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							cnex | 
							   | 
						
						
							| 2 | 
							
								
							 | 
							zsscn | 
							   | 
						
						
							| 3 | 
							
								1 2
							 | 
							ssexi | 
							   |