RealInterval needing N

*To*: MATHGROUP at yoda.physics.unc.edu*Subject*: RealInterval needing N*From*: fateman at peoplesparc.berkeley.edu (Richard Fateman)*Date*: Sat, 10 Oct 92 16:51:15 PDT

There's lots more wrong with RealInterval in Mathematica 2.0 (and I suspect in later versions). The concept of interval arithmetic in computational mathematics requires that the result of an interval operation f on an interval I includes every value f(a) where a is in I. Mathematica does not obey this rule. I suspect that this really is a consequence of its notion of precision and accuracy, plus some sloppiness in defining RealInterval. RJF