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  1. getlength(L,N) :-
  2.     retractall(getlength_res(_)),
  3.     assert(getlength_res(0)),
  4.     retractall(getlength_list(_)),
  5.     assert(getlength_list(L)),
  6.     repeat,
  7.         (
  8.             getlength_list([]), !, getlength_res(N)
  9.         ;
  10.             retract(getlength_res(V)), W is V + 1, assert(getlength_res(W)),
  11.             retract(getlength_list([_|T])), assert(getlength_list(T)), fail
  12.         ).
  13.  
  14. main:-
  15. 	getlength([1,2,3,4,5,6], X),
  16. 	writeln(X),
  17. 	getlength([], Y),
  18. 	writeln(Y)
  19. 	.
  20.  
  21. :- main.
Success #stdin #stdout #stderr 0.02s 6160KB
comments (?)
stdin 
Standard input is empty
stdout 
6
0
stderr 

    

	
			

					
			
			
			
			
			
			
			
			

			
			
			
		

	
		
		

			


			                        
			
			

				

	
					
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language:

						
Prolog (swi 7.6.4)

					

					

						
created:
								
						
9 years ago

					

					

						
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