Integer to string conversion does not work as expected

According to XPath 1.0 specification section 4.2 (http://www.w3.org/TR/xpath#section-String-Functions) the string() function should work this way for integers:

"if the number is an integer, the number is represented in decimal form as a Number with no decimal point and no leading zeros, preceded by a minus sign if the number is negative"

but for example using the string() function on an integer with value 2 results in the string "2.0" which is not correct according to the specification. The result should be the string "2" according to the specification.