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[F&O]: Result of arithmetic involving Inf

From: Henry Zongaro <zongaro@ca.ibm.com>
Date: Tue, 27 Jul 2004 16:37:29 -0400
To: public-qt-comments@w3.org
Message-ID: <OFF873FDD5.5742EC2E-ON85256EDE.006DBC7D-85256EDE.00714A9D@ca.ibm.com>


     According to section 6.2 of the 2004-07-23 Working Draft of F&O, "For 
op:numeric-add, op:numeric-subtract and op:numeric-multiply if either 
operand is INF or -INF the result is NaN."

     I believe that statement is not consistent with IEEE-754. Multiplying 
a zero value by an Infinity, adding Infinities that have opposite signs, 
or subtracting Infinities that have the same sign should result in NaN. In 
addition, adding, subtracting or multiplying an Infinity and a NaN should 
result in a NaN.  Other combinations involving an operand with infinite 
magnitude will result in an infinity with the appropriate sign.


[1] http://www.w3.org/TR/2004/WD-xpath-functions-20040723/#op.numeric
Henry Zongaro      Xalan development
IBM SWS Toronto Lab   T/L 969-6044;  Phone +1 905 413-6044
Received on Tuesday, 27 July 2004 16:37:55 UTC

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