{
  "id": "t4_count_zeros",
  "title": "Count zeros in a list using Eq Int",
  "description": "Write a complete AILang module named t4_count_zeros. It must define a local algebraic data type List a with constructors Nil and Cons a (List a). It must export a top-level function count_zeros : (List Int) -> Int that returns the number of elements in the list that equal 0, using the prelude Eq Int instance to compare against 0. It must also export main : () -> () !IO that prints count_zeros(Nil) and then count_zeros(Cons(0, Cons(5, Cons(0, Cons(3, Cons(0, Nil)))))), each on its own line.",
  "expected_stdout": "0\n3\n",
  "reference_solution": "t4_count_zeros.reference.ail.json"
}