Database BASIC ALGEBRAIC STRUCTURES Subring algebras and ideals Subring algebras sradsOLD  
				
		 
		
			
		 
		Description:   Obsolete version of srads  as of 29-Oct-2024.  Distance function of a
       subring algebra.  (Contributed by Mario Carneiro , 4-Oct-2015)   (Revised by Thierry Arnoux , 16-Jun-2019)   (Proof modification is discouraged.) 
       (New usage is discouraged.) 
		
			
				
					Ref 
					Expression 
				 
					
						Hypotheses 
						srapart.a    ⊢   φ   →   A  =     subringAlg   ⁡  W   ⁡  S          
					 
					
						srapart.s    ⊢   φ   →   S  ⊆  Base  W        
					 
				
					Assertion 
					sradsOLD    ⊢   φ   →    dist  ⁡  W   =   dist  ⁡  A          
				 
			
		 
		
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1 
								
							 
							srapart.a   ⊢   φ   →   A  =     subringAlg   ⁡  W   ⁡  S          
						
							2 
								
							 
							srapart.s   ⊢   φ   →   S  ⊆  Base  W        
						
							3 
								
							 
							df-ds  ⊢   dist  =  Slot   12        
						
							4 
								
							 
							1nn0  ⊢    1   ∈    ℕ   0         
						
							5 
								
							 
							2nn  ⊢    2   ∈   ℕ        
						
							6 
								4  5 
							 
							decnncl  ⊢    12   ∈   ℕ        
						
							7 
								
							 
							1nn  ⊢    1   ∈   ℕ        
						
							8 
								
							 
							2nn0  ⊢    2   ∈    ℕ   0         
						
							9 
								
							 
							8nn0  ⊢    8   ∈    ℕ   0         
						
							10 
								
							 
							8lt10  ⊢    8   <   10        
						
							11 
								7  8  9  10 
							 
							declti  ⊢    8   <   12        
						
							12 
								11 
							 
							olci  ⊢     12   <   5     ∨    8   <   12         
						
							13 
								1  2  3  6  12 
							 
							sralemOLD   ⊢   φ   →    dist  ⁡  W   =   dist  ⁡  A