[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

# in place of a digit.




My intention was to allow any implementation that might try to keep
track of the significance of a number to have a notation that could
indicate that some of the digits are not known.  Thus, a number, such
as 180+-5, that is only known to two significant places could be
described as 18#.  Note that 18# is not quite the same idea as #i180
because #i180 does not try to communicate a measure of our knowledge
of the number whereas 18# is trying to communicate that we know 2
significant places of the number (in decimal).

I have only used this feature in a few experimental cases, where I was
dealing with interval arithmetic.  I believe that it is reasonably
harmless, reserving flexibility for implementors to try to build
interesting representations of inexact numbers that keep track of
significance (to the small extent that it is possible to do so).