Database GRAPH THEORY Walks, paths and cycles Closed walks as words Closed walks of a fixed length as words erclwwlkn  
				
		 
		
			
		 
		Description:   .~  is an equivalence relation over the set of closed walks (defined
       as words) with a fixed length.  (Contributed by Alexander van der
       Vekens , 10-Apr-2018)   (Revised by AV , 30-Apr-2021) 
		
			
				
					Ref 
					Expression 
				 
					
						Hypotheses 
						erclwwlkn.w ⊢  𝑊   =  ( 𝑁   ClWWalksN  𝐺  )  
					
						erclwwlkn.r ⊢   ∼    =  { 〈 𝑡  ,  𝑢  〉  ∣  ( 𝑡   ∈  𝑊   ∧  𝑢   ∈  𝑊   ∧  ∃ 𝑛   ∈  ( 0 ... 𝑁  ) 𝑡   =  ( 𝑢   cyclShift  𝑛  ) ) }  
				
					Assertion 
					erclwwlkn ⊢    ∼    Er  𝑊   
			
		 
		
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1 
								
							 
							erclwwlkn.w ⊢  𝑊   =  ( 𝑁   ClWWalksN  𝐺  )  
						
							2 
								
							 
							erclwwlkn.r ⊢   ∼    =  { 〈 𝑡  ,  𝑢  〉  ∣  ( 𝑡   ∈  𝑊   ∧  𝑢   ∈  𝑊   ∧  ∃ 𝑛   ∈  ( 0 ... 𝑁  ) 𝑡   =  ( 𝑢   cyclShift  𝑛  ) ) }  
						
							3 
								1  2 
							 
							erclwwlknrel ⊢  Rel   ∼    
						
							4 
								1  2 
							 
							erclwwlknsym ⊢  ( 𝑥   ∼   𝑦   →  𝑦   ∼   𝑥  )  
						
							5 
								1  2 
							 
							erclwwlkntr ⊢  ( ( 𝑥   ∼   𝑦   ∧  𝑦   ∼   𝑧  )  →  𝑥   ∼   𝑧  )  
						
							6 
								1  2 
							 
							erclwwlknref ⊢  ( 𝑥   ∈  𝑊   ↔  𝑥   ∼   𝑥  )  
						
							7 
								3  4  5  6 
							 
							iseri ⊢   ∼    Er  𝑊