---
Γ := rules "chars"
  chars := rules "chars" "char"
    chars := rules "chars" "char"
      chars := rules "chars" "char"
        chars := rules "chars" "char"
          chars := rules 
          char := lexemes "CHAR"
            CHAR "a" (1, 1)
        char := lexemes "CHAR"
          CHAR "b" (1, 2)
      char := lexemes "CHAR"
        CHAR "c" (1, 3)
    char := lexemes "CHAR"
      CHAR "d" (1, 4)