Database GRAPH THEORY Walks, paths and cycles Walks as words df-wspthsn  
				
		 
		
			
		 
		Description:   Define the collection of simple paths of a fixed length as word over the
       set of vertices.  (Contributed by Alexander van der Vekens , 1-Mar-2018) 
       (Revised by AV , 11-May-2021) 
		
			
				
					Ref 
					Expression 
				 
				
					Assertion 
					df-wspthsn ⊢    WSPathsN   =  ( 𝑛   ∈  ℕ0  ,  𝑔   ∈  V  ↦  { 𝑤   ∈  ( 𝑛   WWalksN  𝑔  )  ∣  ∃ 𝑓  𝑓  ( SPaths ‘ 𝑔  ) 𝑤  } )  
			
		 
		
				Detailed syntax breakdown 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							0 
								
							 
							cwwspthsn ⊢   WSPathsN   
						
							1 
								
							 
							vn ⊢  𝑛   
						
							2 
								
							 
							cn0 ⊢  ℕ0   
						
							3 
								
							 
							vg ⊢  𝑔   
						
							4 
								
							 
							cvv ⊢  V  
						
							5 
								
							 
							vw ⊢  𝑤   
						
							6 
								1 
							 
							cv ⊢  𝑛   
						
							7 
								
							 
							cwwlksn ⊢   WWalksN   
						
							8 
								3 
							 
							cv ⊢  𝑔   
						
							9 
								6  8  7 
							 
							co ⊢  ( 𝑛   WWalksN  𝑔  )  
						
							10 
								
							 
							vf ⊢  𝑓   
						
							11 
								10 
							 
							cv ⊢  𝑓   
						
							12 
								
							 
							cspths ⊢  SPaths  
						
							13 
								8  12 
							 
							cfv ⊢  ( SPaths ‘ 𝑔  )  
						
							14 
								5 
							 
							cv ⊢  𝑤   
						
							15 
								11  14  13 
							 
							wbr ⊢  𝑓  ( SPaths ‘ 𝑔  ) 𝑤   
						
							16 
								15  10 
							 
							wex ⊢  ∃ 𝑓  𝑓  ( SPaths ‘ 𝑔  ) 𝑤   
						
							17 
								16  5  9 
							 
							crab ⊢  { 𝑤   ∈  ( 𝑛   WWalksN  𝑔  )  ∣  ∃ 𝑓  𝑓  ( SPaths ‘ 𝑔  ) 𝑤  }  
						
							18 
								1  3  2  4  17 
							 
							cmpo ⊢  ( 𝑛   ∈  ℕ0  ,  𝑔   ∈  V  ↦  { 𝑤   ∈  ( 𝑛   WWalksN  𝑔  )  ∣  ∃ 𝑓  𝑓  ( SPaths ‘ 𝑔  ) 𝑤  } )  
						
							19 
								0  18 
							 
							wceq ⊢   WSPathsN   =  ( 𝑛   ∈  ℕ0  ,  𝑔   ∈  V  ↦  { 𝑤   ∈  ( 𝑛   WWalksN  𝑔  )  ∣  ∃ 𝑓  𝑓  ( SPaths ‘ 𝑔  ) 𝑤  } )