ORA-FO-175-B: things you can say about precision of the result

SECTION 6.2: functions and operators on numerics

last sentence before 6.2.1: "The number of digits of precision 
returned...is implementation-dependent."  I think this statement
is only necessary when the return type is xs:decimal.
If the return type is xs:integer, then there are obviously
0 places precision after the decimal point, and the precision 
above is limited by the implementation-defined maximum and 
minimum values for xs:integer.  If the return type is 
xs:float or xs:double, you can say that the operation,
and hence the precision of the result, is dictated by the 
IEEE floating point standard.  As for xs:decimal, the precision
ought to be implementation-defined rather than 
implementation-dependent, which leaves the user completely in the 
dark about the behavior.

- Steve B.