/*
  From MindYourDecisions:
  """
  This comes from a Nexus 7 advertisement from Google Japan. Can you make 10 from the num-
  bers 1, 1, 5, and 8? You have to use each number exactly once, and you are limited to basic oper-
  ations of +, −, ×, ÷, and parentheses ().
  """

  This seems to be the only solution:
    [program = D / (B - A / C),res = 10.0,count = 1]

  I.e. 
   8/(1-(1/5)) = 10

  Cf 
  * symbolic_regression_24_game.pi
  * 24_game.pi (go10/0)

*/
data(problem_8,Data,Vars,Unknown,Ops,Constants,MaxSize,Params) :-
  Data = [[[1,1,5,8],10]],
  Ops = [+,-,*,/],
  Constants = [], % No other values
  Vars = ['A','B','C','D'],
  Unknown = [1,1,5,8],  
  MaxSize = 11,
  Params = new_map([init_size=1000,
                    num_gens=1000,
                    unique_vars_all=true
                   ]).