Metamath Proof Explorer
		
		
		
		Description:  The multiplication operation is a set.  (Contributed by NM, 19-Oct-2004)
     (Revised by Mario Carneiro, 17-Nov-2014)
		
			
				
					|  |  | Ref | Expression | 
				
					|  | Assertion | mulex |  | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ax-mulf |  | 
						
							| 2 |  | cnex |  | 
						
							| 3 | 2 2 | xpex |  | 
						
							| 4 |  | fex2 |  | 
						
							| 5 | 1 3 2 4 | mp3an |  |