Re: Interval Arithmetic project



>>>>> "Richard" == Richard Fateman <fateman at EECS.Berkeley.EDU> writes:

    Richard> Actually, copying down the rules for   <interval> [op]<interval>  from
    Richard> some text  or reference work is not hard. In fact, it should be
    Richard> possible to copy it out of a program or just use existing lisp
    Richard> code.  There are some subtleties regarding rounding at

CMUCL has such interval code, which SBCL has inherited.  It used to be
mostly separatable, but is now kind of mashed into CMUCL internals.
It doesn't, however, do any kind of directed rounding, mostly because
the interval code handles rationals, single-floats, and double-floats,
all via numeric contagion.

    Richard> The difficult part is integrating into maxima the rules that 
    Richard> violate the conventions already in maxima, such as

    Richard> x-x -->  0  for all x.  

    Richard> This is false for intervals.

What is the result?  [-eps, eps], where eps is a floating-point
precision of some sort?

Ray