 	case greaterThanOrEqual
 	case and
 	case or
+	case add
+	case subtract
+	case multiply
+	case divide
 
 	func sql(dialect: SQLDialect) -> String {
 		switch self {

			}
		})

		add_named_rule("ex-equality", rule: ^"ex-value" ~~ ((^"ex-equality-operator" ~~ ^"ex-value") => {
			guard case .expression(let right) = self.stack.popLast()! else { fatalError() }
			guard case .binaryOperator(let op) = self.stack.popLast()! else { fatalError() }
			guard case .expression(let left) = self.stack.popLast()! else { fatalError() }

		case .greaterThanOrEqual: return ">="
		case .and: return "AND"
		case .or: return "OR"
		case .add: return "+"
		case .subtract: return "-"
		case .divide: return "/"
		case .multiply: return "*"
		}
	}
}
