$arg downwards to a whole number.
General rules: see .
The function returns the largest (closest to positive infinity) number with no
fractional part that is not greater than the value of
For the four types
xs:integer, it is
guaranteed that if the type of
$arg is an instance of type T then
the result will also be an instance of T. The result may
also be an instance of a type derived from one of these four by restriction. For example, if
$arg is an instance of
xs:decimal then the result may
be an instance of
xs:double arguments, if the argument is
positive zero, then positive zero is returned. If the argument is negative zero, then
negative zero is returned.