/* 

  Unpredictable prediction in Picat.

  From Chris Smith's Maths Newsletter #547
  """
  I gave Heidi, Logan, and Daisy a whole number I was
  thinking of ... 

   [
      Heidi: I'm multiplying your number by 4 or 5
      Logan: I'll add 4 or 5 to that new number
      Daisy: I'll subtract 4 or 5 from Logan's number.
   ]

  Daisy told me that the final answer to their unpreditable
  calculation was 173.

  What number did I given then to start off with?
  """

  Chris Smith's Twitter feed: https://twitter.com/aap03102

  This model was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/

% import v3_utils.
% import util.
import cp.


main => go.

go ?=>
  LD = [X,H,L,D],
  LD:: 0..200,
  H #= X * 4 #\/ H #= X * 5,
  L #= H + 4 #\/ L #= H + 5,
  D #= L - 4 #\/ D #= L -5,

  D #= 173,
  
  solve(LD),
  println(ld=LD),
  println(x=X),
  fail,  
  nl.
go => true.