[Maxima] unsimplified result from integrate
Barton Willis
willisb at unk.edu
Wed Jan 21 05:12:37 CST 2009
I was looking into bug 2465066 "unsimplified result from integrate." The
bug is
(%i1) matchdeclare(x, symbolp)$
(%i2) tellsimpafter('integrate(f(x),x), g(x))$
(%i3) integrate(5*f(x)+7,x);
(%o3) 5*integrate(f(x),x)+7*x
(%i4) expand(%,0,0);
(%o4) 5*g(x)+7*x
In sinint (sin.lisp), I see
((let ((ans (simplify
(let ($opsubst varlist genvar stack)
(integrator exp var)))))
(if (sum-of-intsp ans)
(list '(%integrate) exp var)
ans))))))
Changing simplify to ($expand ... 0 0) fixes the bug. I'm not sure why
($expand ... 0 0) works and simplify doesn't. Maybe the code needs to be
fixed elsewhere. Advice? Is ($expand ... 0 0) an OK fix?
Barton
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