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Text File  |  1990-05-25  |  412b  |  19 lines
  1. % generated: 25 October 1989
  2. % option(s): 
  3. %
  4. %   nreverse
  5. %
  6. %   David H. D. Warren
  7. %
  8. %   "naive"-reverse a list of 30 integers
  9.  
  10. nreverse :- nreverse([1,2,3,4,5,6,7,8,9,10,11,12,
  11.               13,14,15,16,17,18,19,20,21,
  12.               22,23,24,25,26,27,28,29,30],_).
  13.  
  14. nreverse([X|L0],L) :- nreverse(L0,L1), concatenate(L1,[X],L).
  15. nreverse([],[]).
  16.  
  17. concatenate([X|L1],L2,[X|L3]) :- concatenate(L1,L2,L3).
  18. concatenate([],L,L).
  19.