Metamath Proof Explorer
		
		
		
		Description:  The functor from the empty category.  (Contributed by Zhi Wang, 7-Oct-2025)  (Proof shortened by Zhi Wang, 17-Oct-2025)
		
			
				
					 | 
					 | 
					Ref | 
					Expression | 
				
					
						 | 
						Hypothesis | 
						0func.c | 
						   | 
					
				
					 | 
					Assertion | 
					0func | 
					   | 
				
			
		
		
			
				Proof
				
					
						| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							0func.c | 
							   | 
						
						
							| 2 | 
							
								
							 | 
							0ex | 
							   | 
						
						
							| 3 | 
							
								2
							 | 
							a1i | 
							   | 
						
						
							| 4 | 
							
								
							 | 
							base0 | 
							   | 
						
						
							| 5 | 
							
								4
							 | 
							a1i | 
							   | 
						
						
							| 6 | 
							
								3 5 1
							 | 
							0funcg | 
							   |