I think the problem is with the return value for asksign:
(%i4) asksign(xxx^2);
Is xxx zero or nonzero?
nonzero;
(%o4) zero
(%i5) asksign(xxx^2);
Is xxx zero or nonzero?
zero;
(%o5) zero
(%i6)
This integral of x^n uses a defprop on mexpt (look in sin.lisp). There is an asksign that always returns zero--that chooses the log option.
--Barton
________________________________________
From: maxima-bounces at math.utexas.edu [maxima-bounces at math.utexas.edu] on behalf of Raymond Toy [toy.raymond at gmail.com]
Sent: Sunday, May 19, 2013 11:42
To: maxima at math.utexas.edu
Subject: Regression in integration
I was looking at a message from Harry Christhian[1] about a bug in
integration, which I didn't quite understand, but I found the
following serious error:
(%i1) integrate(c/x^n,x);
Is n - 1 zero or nonzero?
nonzero;
(%o1) c log(x)
It doesn't matter whether you answer zero or nonzero; you get the
answer as if n = 1.
Ray
[1] Is it possible to directly send email to maxima-bugs? Or should
only the bug tracker send email to that list? Anyway, I think he's
saying integrate(c/x^n,x) returns -c/(1-n)*x^(1-n) but he wants
-c/(n-1)/x^(n-1).
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