Metamath Proof Explorer
		
		
		
		Description:  If the domain of a function is a set, the function is a set.
       (Contributed by Glauco Siliprandi, 23-Oct-2021)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | fnexd.1 |  | 
					
						|  |  | fnexd.2 |  | 
				
					|  | Assertion | fnexd |  | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fnexd.1 |  | 
						
							| 2 |  | fnexd.2 |  | 
						
							| 3 |  | fnex |  | 
						
							| 4 | 1 2 3 | syl2anc |  |