/*
  Fibonacci closed form.


  This crashes Picat and is reported to NFZ:
  - floor(exp(floor(3) / exp(-6.591089771404439)))
  - floor(exp(exp(11.937601339042931 + 1)))
  - floor(exp(exp(8)))
  So we use ceiling/1 instead.


  * I stopped it after 2hours:
    gen = 39879  (time: 6741.483s)
    results_best = [[38.909123964266598,(sqrt(exp(X) / X) - 3) / (11.937601339042931 / (11.937601339042931 + sqrt(X)))]]

  * stop_criteria=generations num_gens=1800
    gen = 1764  (time: 100.014s)
    results_best = [[474.308232046410126,floor(X - 4 + sqrt(exp(X))) / sqrt(10)]]

    gen = 1283  (time: 67.621s)
    results_best = [[245.063568941527564,sqrt(exp(X) - X) / sqrt(sqrt(exp(sqrt(floor(X))) + (X + 13.607508686188382)))]]


  Cf fib_50_2.conf

*/
import util.
data(eureqa_test,Data,Vars,Unknown,Ops,Constants,MaxSize,Params) :-
  Data = [ [[A],B] : A in 1..20, fib(A)=B],
  % Ops = [+,/,-,exp,sqrt,ceiling],
  Ops = [+,/,-,exp,sqrt,floor,pow_mod2],  
  Constants = 0..10 ++ [frand(-20,20) : _ in 1..10],
  Vars = ['X'],
  Unknown = [1],
  MaxSize = 51,
  Params = new_map([
                    approx=1,
                    stop_criteria=generations,
                    num_gens=1800
                   ]).

table
fib(0) = 0.
fib(1) = 1.
fib(N) = fib(N-1) + fib(N-2).