[Tim Peters] ... > One clever way is to build on that whenever |x| and |y| are within a > factor of 2 of each other, x+y is exact in 754 arithmetic.
Ack, I'm fried. Forget that, it's wrong. The correct statement is that x-y is always exact whenever x and y are within a factor of two of each other. Summer.add() _can_ lose info -- it needs additional trickery to make it loss-free, and because x+y can lose (at most one bit) when x and y have the same binary exponent. Exercise for the abused reader <wink>. _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
