On Fri, Oct 24, 2008 at 9:56 PM, Richard Hennessy <rvh2007 at comcast.net>wrote:
> I copied this from the documentation.
> "When assume_pos is true and the sign of a parameter x cannot be determined
> from the current context or other
> considerations, sign and asksign (x) return true. This may forestall some
> automatically-generated asksign queries, such
> as may arise from integrate or other computations. "
> ...
> These two plots are not the same and one is really wrong even given the
> context obtained from the help.
>
Perhaps we can also improve the phrasing of the documentation. "Context"
here presumably refers to the assume-database context, not to
syntactic/semantic context in general. For example, you might think that
the "context" of abs(x) in
limit(abs(x),x,-1)
is that x is in a neighborhood of -1, and therefore negative, but that is
not what the doc was referring to.
So the doc should read "...determined from the current assume database
context..." and not even mention "other considerations", which just invites
the reader to imagine what it might be taking into account.
-s