[Axiom-developer] [#180 bug #9216 differentiating sums with respect to a bound is wrong] Mail from Manuel Bronstein

[kratt6]

Changes 
http://page.axiom-developer.org/zope/mathaction/180Bug9216DifferentiatingSumsWithRespectToABoundIsWrong/diff
--
Hello,

I finally took at look at your patch 3148 on dvdsum.
Your changes to dvdsum are fine, however the lines::

+    ddiff l ==
+      prefix(sub(D::O, third(l)::O), [eval(first(l), second(l), third(l))::O])
+
and
+    setProperty(opdiff, SPECIALDISP, ddiff@(List F -> O) pretend None)

should be removed from the code: this property is being set in fspace.spad
already, and you are duplicating that code (with differences). Each source
file initializes the properties of the operators that it is particularly
responsible for. CommonOperators() ensures that the operators are shared by 
the clients, so the opdiff you are getting in combfunc.spad will have its
SPECIALDISP property set by fspace.spad at some point before it ever gets
displayed.

Sorry that I don't know how to update your patch on savannah, I would have
done so directly otherwise.

Regards,

-- mb
--
forwarded from http://page.axiom-developer.org/zope/mathaction/address@hidden