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Question: Error, (in SolveTools:-Polynomial) too many levels of recursion when using alias

Question:Error, (in SolveTools:-Polynomial) too many levels of recursion when using alias

nm 9698 Maple 2022
ode differential-equations alias odetest
June 15 2023
2

I found another big problem. 

In 2022, I get Error, (in SolveTools:-Polynomial) too many levels of recursion when using alias(seq(c[k] = _C||k, k = 0..10)); at the top of my code and the solution to the ode has c[2],c[3] etc.. as constants of integration.

This solution was given by Kitonum in this answer

I had this for years in the code (i.e. the alias) code.

In Maple 2022 the following gives the above exception error from odetest. I am using 2022, because in 2023 it just hangs on the same code.  

If I remove the alias code, no error shows. (solution is wrong, but that is different story). 

Also, If I remove the alias code, 2023 no long hangs!  

> 

restart;
> 

#kernelopts('assertlevel'=2):
> 

alias(seq(c[k] = _C||k, k = 0..10));

c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7], c[8], c[9], c[10]

> 

ode:=diff(diff(y(x),x),x)+4*diff(y(x),x)+12*y(x) = 80*sin(2*x);
sol:=y(x) = -10*exp(-1/2*2^(1/2)*arctan(sin(2*2^(1/2)*x)/cos(2*2^(1/2)*x)))*(c[3]*cos(2*2^(1/2)*x)+c[2]*sin(2*2^(1/2)*x))*((-1/10*exp(4*I*2^(1/2)*x)+1/10)*c[2]-1/10*I*c[3]*exp(4*I*2^(1/2)*x)-1/10*I*c[3])/((exp(4*I*2^(1/2)*x)-1)*c[2]+I*c[3]*exp(4*I*2^(1/2)*x)+I*c[3])*c[1]-10*I*exp(-1/2*2^(1/2)*arctan(sin(2*2^(1/2)*x)/cos(2*2^(1/2)*x)))*(c[3]*cos(2*2^(1/2)*x)+c[2]*sin(2*2^(1/2)*x))*(cos(2*x)-sin(2*x))*exp(2*I*2^(1/2)*x)*exp(2*I*2^(1/2)*x)^(-1/2*I*2^(1/2))/((exp(4*I*2^(1/2)*x)-1)*c[2]+I*c[3]*exp(4*I*2^(1/2)*x)+I*c[3]);

odetest(sol,ode);

diff(diff(y(x), x), x)+4*(diff(y(x), x))+12*y(x) = 80*sin(2*x)

y(x) = -10*exp(-(1/2)*2^(1/2)*arctan(sin(2*2^(1/2)*x)/cos(2*2^(1/2)*x)))*(c[3]*cos(2*2^(1/2)*x)+c[2]*sin(2*2^(1/2)*x))*((-(1/10)*exp((4*I)*2^(1/2)*x)+1/10)*c[2]-((1/10)*I)*c[3]*exp((4*I)*2^(1/2)*x)-((1/10)*I)*c[3])*c[1]/((exp((4*I)*2^(1/2)*x)-1)*c[2]+I*c[3]*exp((4*I)*2^(1/2)*x)+I*c[3])-(10*I)*exp(-(1/2)*2^(1/2)*arctan(sin(2*2^(1/2)*x)/cos(2*2^(1/2)*x)))*(c[3]*cos(2*2^(1/2)*x)+c[2]*sin(2*2^(1/2)*x))*(cos(2*x)-sin(2*x))*exp((2*I)*2^(1/2)*x)*(exp((2*I)*2^(1/2)*x))^(-((1/2)*I)*2^(1/2))/((exp((4*I)*2^(1/2)*x)-1)*c[2]+I*c[3]*exp((4*I)*2^(1/2)*x)+I*c[3])

Error, (in SolveTools:-Polynomial) too many levels of recursion

> 

 

Download odetest_error_june_15_2023.mw

Why using the alias line above causes this error?  If you remove the alias line, you will see it completes with no error.

But it hangs in 2023. I am no longer using 2023 but went back to 2022 due to too many hangs in 2023. I wonder now if it because of this alias line I had there all the time.  I will remove now and see if this solves some of the hangs I had in 2023.

Anyone can shed some more light on what is going on?

Windows 10.
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