task_16.pr

DOMAINS
	list=i*
	i=integer
	
PREDICATES
	nondeterm main()
	nondeterm input_list(list)
	nondeterm make_positive(list, list)
	nondeterm print_list(list)
	
CLAUSES
	main():-
		input_list(L),
		make_positive(L, NewL),
		print_list(NewL).
		
	input_list([H|T]):-
		write(">> "),
		readint(H),
		input_list(T).
		
	input_list([]).
	
	make_positive([],[]).
	
	make_positive([H|T1], [H|T2]):-
		H >= 0,
		make_positive(T1, T2).
		
	make_positive([H1|T1], [H2|T2]):-
		H1 < 0,
		H2 = -H1,
		make_positive(T1, T2).

	print_list([]).
		
	print_list([H|T]):-
		write(H, " "),
		print_list(T).

GOAL
	main().