Maciej Radziejewski on Mon, 11 Aug 2003 17:36:54 +0200   Real
numbers accuracy.   I tried the following evaluations:  \\ 0.E-9
\\ 0.E-19  The claimed accuracy keeps getting higher through
arithmetic operations. The effect is the same under the
experimental and stable Pari. Is it meant to work like that, or
is it a bug?  If it is supposed to be like that, is there a Pari
feature, or extension, where one could get a rigorous accuracy
estimate? Such a feature would be very useful for theorem
proving using analytic methods. If I wanted to define arithmetic
operations on pairs (z, r), where z is a complex made of reals
and r is the upper estimated absolute value of an error, does it
require tampering with Pari's source code?    Do you Yahoo!?