[Maxima-discuss] Error in solve with orderless called before

[Andrii S. <and...@gm...>]

Dear all,

Recently I was not able to use 'solve' for an elementary linear equation---
if 'orderless' was called before. The commands are invoked are the following
(sorry for a lengthy input):

orderless(w1, w2, W1, W2, k1, k2, g, f1, f2, K)$

eq : -%i*W1*B10 = K * ((%i*g*f1^3)/((%i*w1-%i*W1+k1)*((-%i*w1)+%i*W1+k1)
                                                  *((-w1*w2)+(w1+w2)*W1-W1^2
                                                            +(%i*w2-%i*W1)*k1
                                                            +(%i*w1-%i*W1+k1)
                                                             *k2))
                  -(%i*g*f1*f2^2)/((%i*w1-%i*W1+k1)*(%i*w2-%i*W2+k2)
                                                   *((-w1*w2)+(w1+w2)*W2-W2^2
                                                             +((-%i*w2)+%i*W2)
                                                              *k1
                                                             +((-%i*w1)
                                                              +%i*W2+k1)
                                                              *k2))
                  +(%i*g^3*f1*f2^2)/(((-w1*w2)+(w1+w2)*W1-W1^2+(%i*w2-%i*W1)*k1
                                              +(%i*w1-%i*W1+k1)*k2)
                                    *((-w1*w2)+(w1+w2)*W2-W2^2+(%i*w2-%i*W2)*k1
                                              +(%i*w1-%i*W2+k1)*k2)
                                    *((-w1*w2)+(w1+w2)*W2-W2^2
                                              +((-%i*w2)+%i*W2)*k1
                                              +((-%i*w1)+%i*W2+k1)*k2)))

                  +(%i*g
                      *(((-w1*w2^2)+w2^2*W1+(2*w1*w2-2*w2*W1)*W2
                                   +((-w1)+W1)*W2^2
                                   +(%i*w2^2-2*%i*w2*W2+%i*W2^2)*k1
                                   +((-w1)+W1+%i*k1)*k2^2)
                       *f1
                       +f1*f2^2*K))
                   /((-w1^2*w2^2)+2*w1*w2^2*W1-w2^2*W1^2
                                 +(2*w1^2*w2-4*w1*w2*W1+2*w2*W1^2)*W2
                                 +((-w1^2)+2*w1*W1-W1^2)*W2^2
                                 +(2*%i*w1*w2^2-2*%i*w2^2*W1
                                               +((-4*%i*w1*w2)+4*%i*w2*W1)*W2
                                               +(2*%i*w1-2*%i*W1)*W2^2)
                                  *k1+(w2^2-2*w2*W2+W2^2)*k1^2
                                 +((-w1^2)+2*w1*W1-W1^2+(2*%i*w1-2*%i*W1)*k1
                                          +k1^2)
                                  *k2^2)$

solve(eq, B10);

which spits out:

PQUOTIENT: Quotient by a polynomial of higher degree (case 1)

Also if the rhs includes '- %i*w2*B10-k2*B10' additionaly, it diagnoses
'case 2a' in the same PQUOTINENT message. In both cases 'solve' provides
an answer if 'orderless' was not called.

I played a bit removing different parts of the equation and it was unclear
for me what causes an error.

Could that be a bug? Probably related to https://sourceforge.net/p/maxima/bugs/3273/
and the discussion https://maxima-discuss.narkive.com/yE8zdESX/quotient-by-a-polynomial-of-higher-degree

I use Maxima 5.46.0 with GCL 2.6.12 from the RHEL 8 repo.

Regards,
Andrii