Database GRAPH THEORY Vertices and edges The edge function extractor for extensible structures basendxltedgfndx  
				
		 
		
			
		 
		Description:   The index value of the Base  slot is less than the index value of the
     .ef  slot.  (Contributed by AV , 21-Sep-2020)   (Proof shortened by AV , 30-Oct-2024) 
		
			
				
					Ref 
					Expression 
				 
				
					Assertion 
					basendxltedgfndx   ⊢   Base  ndx <    ef   ⁡  ndx        
				 
			
		 
		
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1 
								
							 
							1nn  ⊢    1   ∈   ℕ        
						
							2 
								
							 
							8nn0  ⊢    8   ∈    ℕ   0         
						
							3 
								
							 
							1nn0  ⊢    1   ∈    ℕ   0         
						
							4 
								
							 
							1lt10  ⊢    1   <   10        
						
							5 
								1  2  3  4 
							 
							declti  ⊢    1   <   18        
						
							6 
								
							 
							basendx  ⊢   Base  ndx =   1        
						
							7 
								
							 
							edgfndx  ⊢     ef   ⁡  ndx   =   18        
						
							8 
								5  6  7 
							 
							3brtr4i  ⊢   Base  ndx <    ef   ⁡  ndx