Decimal ← t:Digit u:Decimal → { t * 10 + u } / d:Digit → d Digit ← "0" → 0 / "1" → 1 / "2" → 2 / "3" → 3 / "4" → 4 / "5" → 5 / "6" → 6 / "7" → 7 / "8" → 8 / "9" → 9