Hello, Richard.
Finally I found, that
> 1. "Quotient is not exact" is always the result of a bug. It
> comes from computing the GCD G of two polynomials P, Q, and reducing
> the fraction P/Q to P/G / Q/G. But it finds that G does
> not divide P or Q. So it is a GCD bug. Try changing the GCDSWITCH
> to use a different GCD algorithm.
no GCDSWITCH is defined anywhere in Maxima-5.9.0/* subdirectories. Maybe
something's missing in the distribution? The switches are only mentioned
in one .dem file :(
>
> 3. Try, after substitution, to use ratsimp or radcan.
>
it doesn't help. Maxima doesn't see that sqrt(2*sqrt(11)+12) =
1+sqrt(11). I wish I could teach it handle nested radicals if I only
knew the proper algorithm.
--
Andrei Zorine