Problems with linsolve: quotient by polynomial of higher degree

On 05/26/2012 11:51 AM, Stefano Ferri wrote:
> I've attached a file, which can be batched, containing the simplest example
> I've found for this problem. There are some polynomials up to the 9-th
> order in l, are these the cause of the problem? If l is set to a numeric
> value the problem disappears (even though the solution is quite
> complicated).

Perhaps I have a related issue with polynomialp.
I have taken the 3rd equation from the file of Stefano Ferri and did

------------- polynomialp-1.max ----------------
display2d : false;

h :  2*_x9*E*I/(l+1)-6*_x8*E*I/(l^2+2*l+1)+2*_x6*E*I/l-3*_x5*E*I/l^2
                 +3^(3/2)*_x4*E*I/l^2+8*l*_x3*E*I/(l^2+l)+4*_x3*E*I/(l^2+l);
print(h);
print(polynomialp(h,[_x9]));
------------- polynomialp-1.max ----------------

I got
------------------------------------------------

[user at host tmp]$ maxima -b polynomialp-1.max
Maxima 5.26.0 http://maxima.sourceforge.net
using Lisp SBCL 1.0.56
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
STYLE-WARNING: redefining MAXIMA::$FILE_TYPE in DEFUN
(%i1)                      batch(polynomialp-1.max)

read and interpret file: /home/user/tmp/polynomialp-1.max
(%i2)                          display2d : false
(%o2) false
(%i3) h:4*_x3*E*I/(l+l^2)+8*l*_x3*E*I/(l+l^2)+3^(3/2)*_x4*E*I/l^2
                          
+(-3*_x5*E*I)/l^2+2*_x6*E*I/l-6*_x8*E*I/(1+2*l+l^2)
                          +2*_x9*E*I/(1+l)
(%o3) 2*_x9*E*I/(l+1)-6*_x8*E*I/(l^2+2*l+1)+2*_x6*E*I/l-3*_x5*E*I/l^2
                      +3^(3/2)*_x4*E*I/l^2+8*l*_x3*E*I/(l^2+l)
                      +4*_x3*E*I/(l^2+l)
(%i4) print(h)
2*_x9*E*I/(l+1)-6*_x8*E*I/(l^2+2*l+1)+2*_x6*E*I/l-3*_x5*E*I/l^2
                +3^(3/2)*_x4*E*I/l^2+8*l*_x3*E*I/(l^2+l)+4*_x3*E*I/(l^2+l)

(%o4) 2*_x9*E*I/(l+1)-6*_x8*E*I/(l^2+2*l+1)+2*_x6*E*I/l-3*_x5*E*I/l^2
                      +3^(3/2)*_x4*E*I/l^2+8*l*_x3*E*I/(l^2+l)
                      +4*_x3*E*I/(l^2+l)
(%i5) print(polynomialp(h,[_x9]))
nil
(%o5) false
(%o5) "/home/user/tmp/polynomialp-1.max"
------------------------------------------------

But h is clearly a polynomial in _x9.

Andre