boolean :: Parser BooleanExp
boolean =   true 
        <|> false
        <|> try (arithmeticComparison)
        <|> parens booleanExpression
boolean :: Parser BooleanExp
boolean =   true 
        <|> false
        <|> try (arithmeticComparison)
        <|> parens booleanExpression
boolean =   true 
        <|> false
        <|> try (arithmeticComparison)
        <|> parens booleanExpression