I am not able to make a MWE for this error, as it only shows in the debugger. So it seems Maple internal memory changes or some other library is loaded to cause this. Inside the debugger, I get to a function which does this

DBG> simplify(JacobiDN(x,k)^2*n)

Error, invalid input: simplify/Jacobi/JacobiDN expects its 1st argument, k, to be of type posint, but received 0

Version 2023 on windows 10

In a worksheet, the above works just fine

restart;
simplify(JacobiDN(x,k)^2*n)

Back to the debugger, if I write (2*n) instead of 2*n, then the error goes away

DBG> simplify(JacobiDN(x,k)^(2*n))
JacobiDN(x,k)^(2*n)

The values of x,k,n are all symbols and have no values in the code running:

I have no idea why this happend when I run the code only. It think x is zero in the above for some reason.

Sorry can't make MWE, I wish I can. Something strange happens when I run the code that does not show otherwise. 

Any suggestions how to invetigate this more? Stepping into the simplify code it fails in

DBG> next
`simplify/check_constant`:
   3   return type(r,'And(constant,Or(Not(function),satisfies(f -> evalb(op(f)
         <> NULL))))')

DBG> r
JacobiDN(x,k)^2*n^2

DBG> type(r,'And(constant,Or(Not(function),satisfies(f -> evalb(op(f)          <> NULL))))')
false

DBG> step
`simplify/Jacobi`
`simplify/do`:
  84               userinfo(1,simplify,'applying',new_simp,
                     `function to expression`);

 85               new_r := new_simp(r,symb_mode);  

Here it generate the error.

It has nothing to do with simplify. Here is a call to integrate which gives same error

DBG> lhs(ode)
diff(diff(xi(x),x),x)-k^2*JacobiSN(x,k)*JacobiCN(x,k)/JacobiDN(x,k)*diff(xi(x),x)+(-k^2*JacobiCN(x,k)^2+k^2*JacobiSN(x,k)^2-k^4*JacobiSN(x,k)^2*JacobiCN(x,k)^2/JacobiDN(x,k)^2-JacobiSN(x,k)^2*k^2*n^2+n^2)*xi(x)

DBG> int(lhs(ode),x)
Error, invalid input: simplify/Jacobi/JacobiDN expects its 1st argument, k, to be of type posint, but received 0

DBG> x
x

DBG> k
k

DBG> xi(x)
xi(x)

alias(b = JacobiCN(sqrt(2)*sqrt(x), sqrt(2)*_Z/2)^2);
                          lessthan, b

I could not find an explanation on the help page.

I would have expected simply b as the return value.

Update:
A worksheet that generates the output

Download alias_with_lessthan_output.mw

If I understand right, the form  is equivalent to  (where the optional index variable is omitted), which produces a sequence of n occurrences of y. But how to explain the following output (of )? 

Download singular_behaviour_of_`seq`.mw

Main code: 

p1 := proc()
    local a := 1, b := 2;
    seq('assign(('a', 'b') = (a + 1, 2*b))', 3);
    print(a, b)
end:

p1():

Hi,

I am exploring the Grading package in Maple, and I want to create a random question about limits. (Question 9). Any ideas for the correct code? Thank you

QUIZZTestMaple.mw

I had purchached reseach licience Maple 2022 towards the end of 2022 only and Quantum Chemistry Toolbox I purchased in Feb 2022 only.

Now i find significant update in toolbox in just 3 months. Now guide me how should i address this issuse.

I had to take loan in india to buy the toolbox.

It is only 3 months.

Can you suggest me how solve the problem to get the update without spending again.

What is the way guide someone.

Ever wonder how to show progress updates from your executing code without printing new lines each time?

One way to do this is to use a TextArea component and the DocumentTools package. The TextArea could be inserted from the Components Palette in Maple, or programmatically like so:

Download text-area-update-progress.mw

y'' + 1/x * u' + u = 6 - 9x + x^2 - x^3

with baundary condition :

u(0) = 0 , and u(1) = 0

Assuming I have an expression

you can know that the derivative with respect to y will vanish when y is a constant y0.

How can we use the mathematical software Maple to simplify this expression?

There appears to be a bug in Maple 2023 where constants beginning with a Greek letter cannot be saved.  Assigning a constant to a Greek letter works in the Maple interface but does not work when reading an MPL file encoded as UTF-8.  Example:

read "D:/Nikki/docs/Maple/constants.mpl" :

MPL file contents:

alias(asec=arcsec) : # arcsecant

ζX1 := asec(1) : # first airmass zenith angle
ζX2 := asec(2) : # second airmass zenith angle

The constant "ζX1" can be assigned/saved in Maple but shows as unassigned when imported from an MPL file encoded as UTF-8.

Any assistance in how to use Greek letters in MPL files is much appreciated.

Maple 2023 still can't verify its own series solution. This happens with Frobenius method when the indicial root are repated. I think I mentioned or reported this long time ago but unable to find a link now.

My question is: Since this looks like it will not be fixed by Maplesoft anytime soon, any one could suggest an alternative method to verify this solution?

restart;

ode:=2*x^2*diff(y(x), x, x) + 2*x*diff(y(x), x) - x*y(x) =0;
sol:=dsolve(ode,y(x),'series');
odetest(sol,ode,'series')

Maple's solution is correct, I solved it by hand and get same solution.

Maple 2023 on windows 10.

I could not find a way to check whether or not a given value belongs to an interval expressed as RealRange (or a union of them e.g. RealRange(Open(-10),-5), RealRange(Open(-6),infinity).

Ideally, I would like a Boolean function that takes two arguments (i) a value v and (ii) a (union of) RealRange r, and returns true/false depending on whether or not value v is in/out of the range r.

When trying to load/import/read an MPL file with Maple 2023, I get an error message of "Error, recursive assignment" which only links to a page which states "There is no help page available for this error."

https://www.maplesoft.com/support/help/errors/view.aspx?path=Error,%20recursive%20assignment

Presumably there is an error in the Maple syntax that prevents execution, but I cannot find a way to debug.  Maple Code Editor Diagnostics says "No Errors" but Maple Code Editor Console says "Error: recursive assignment."  The MPL file is 485 lines but I am assuming the error could be anywhere in the file.  Is there any way to fix this?

Update: I found the error by copying just a handful of lines at a time into Maple until the error was reproduced.  It was a typo of just one character out of 16,960 characters.  But this is very frustrating.  Why can't Maple 2023 tell me what line the error is on?  Is there a better way to debug MPL files?

Why is a change in the text area component triggering an action three times in a row?

Download ThePostmanKnocksThreeTimes.mw

This code fails in Maple 2023.  It used to work in earlier versions.  Did I miss something in the release notes?