OL)
parseNot = reservedOps ["Not", "NOT", "not", "~", "!", "¬"] >> return Not

parseExists, parseForAll ::
parseNot :: Parser (FOL -> FOL)
parseNot = reservedOps ["Not", "NOT", "not", "~", "!", "¬"] >> return Not
parseNot = reservedOps ["Not", "NOT", "not", "~", "!", "¬"] >> return Not