---
Γ := rules "expr"
  expr := rules "bin_op"
    bin_op := rules "expr" "subtract" "expr"
      expr := rules "bin_op"
        bin_op := rules "expr" "divide" "expr"
          expr := rules "bin_op"
            bin_op := rules "expr" "multiply" "expr"
              expr := rules "bin_op"
                bin_op := rules "expr" "add" "expr"
                  expr := rules "int"
                    int := lexemes "INT"
                      INT "1" (1, 1)
                  add := lexemes "+"
                    + "+" (1, 3)
                  expr := rules "int"
                    int := lexemes "INT"
                      INT "2" (1, 5)
              multiply := lexemes "*"
                * "*" (1, 7)
              expr := rules "int"
                int := lexemes "INT"
                  INT "3" (1, 9)
          divide := lexemes "/"
            / "/" (1, 11)
          expr := rules "int"
            int := lexemes "INT"
              INT "6" (1, 13)
      subtract := lexemes "-"
        - "-" (1, 15)
      expr := rules "int"
        int := lexemes "INT"
          INT "7" (1, 17)