---
Γ := rules "sum"
  sum := rules "sum" "plus" "sum"
    sum := rules "sum" "plus" "sum"
      sum := lexemes "INT"
        INT "10" (1, 1)
      plus := lexemes "PLUS"
        PLUS "+" (1, 4)
      sum := lexemes "INT"
        INT "20" (1, 6)
    plus := lexemes "PLUS"
      PLUS "+" (1, 9)
    sum := lexemes "INT"
      INT "30" (1, 11)
---
Γ := rules "sum"
  sum := rules "sum" "plus" "sum"
    sum := lexemes "INT"
      INT "10" (1, 1)
    plus := lexemes "PLUS"
      PLUS "+" (1, 4)
    sum := rules "sum" "plus" "sum"
      sum := lexemes "INT"
        INT "20" (1, 6)
      plus := lexemes "PLUS"
        PLUS "+" (1, 9)
      sum := lexemes "INT"
        INT "30" (1, 11)