[config] lab 3.
root (3, 1) {
  func decl (3, 1) {
    return type: bool
    name: foo
    params (3, 1) {
      decl (3, 10) { int x }
    }
  }
  func defn (5, 1) {
    func decl (5, 1) {
      return type: int
      name: main
      params (5, 1) {
      }
    }
    suite (5, 12) {
      for (6, 2) {
        (null)
        (null)
        (null)
        suite (6, 11) {
          var decl (7, 3) {
            decl (7, 3) { int x }
            int (7, 11) { 3 }
          }
          var decl (8, 3) {
            decl (8, 3) { int y }
            binary expr (8, 11) {
              plus
              unary expr (8, 11) {
                minus
                int (8, 12) { 3 }
              }
              binary expr (8, 16) {
                star
                var (8, 16) { x }
                int (8, 20) { 5 }
              }
            }
          }
          expr stmt (9, 3) {
            ternary expr (9, 3) {
              call (9, 3) {
                function: foo
                args (9, 3) {
                  int (9, 7) { 6 }
                }
              }
              int (9, 12) { 7 }
              int (9, 17) { 8 }
            }
          }
        }
      }
      return (11, 2) {
        int (11, 9) { 0 }
      }
    }
  }
}