Accuracy and the power function

[Werner]

(02-23-2014 02:19 PM)Dieter Wrote:  I see. So this sticky bit avoids some errors caused by simple truncation.

No, it is necessary to implement round to even. It allows to know whether you're in the 'half-way' situation, where the lost digits are exactly 500.
The 10/13 calculators (41,15) did not implement round-to-even, but simple round up (well 'away from zero'). Whether the lost digits are 500 or 500+ makes no difference there, see Tomas' examples.
I know nothing of the accuracy of the 15-digit functions I'm afraid.
Werner