I have deleted a duplicate of this.

Submitting a duplicate of this item is not justified by the fact that the OP is not satisfied by the amount of response here.

If the OP doesn't care for the title used here, then it can be edited.

Additional details can be added in Replies, or edits to the Question body.

If you uploaded a worksheet with an instance of your "unable to parse" problem then we might be able to pinpoint the cause.

You should tell us which input mode you're using, ie. 1D Maple Notation (plaintext), or 2D Input (typeset math).

But a concrete example of the syntax problem would be best.

@Ali Guzel  It appears that the OP is interested in multivariate systems, for which fsolve does not currently have support of a maxsols option.

@Carl Love I think that there is a bug in the special case of using legend alongside filledregions in contourplot, with anything but the default number of 8 contours.

But it's not that complicated to combine a sequence of implicitplots instead.

Something like this, perhaps, assuming my color bookkeeping is right,

Dynamisches_Modell_Final_filled_impls.mw

I suggest you double check that I got matching colors there. I rushed it. Adjust as needed.

Which version of Maple do you use?

@vv I don't deny a problem in the symbolic summation here. But that route is unnecessary all the same.

Even if the symbolic summation worked (and produced some valid representation in terms of the unspecified symbolic name k) then I'd still recommend the direct addition for this particular example.

Here's an alternate that looks more like your followup image. Also in Maple 17.02.

Download listcontdens2_M17.mw

@asaa Your Question's title has it as "xmaple 2020.2" but the body of your Question has it as "xmaple 2021.1". Which is it?

Maple comes bundled with a JRE, so why (and how) are you not using that? For Maple 2021.2 on Linux it is (IIRC) openjdk version "17" 2021-09-14 (build 17+35).

@jalal Explain how you want it animated. Provide that here.

Please don't submit a separate Question thread for this.

If this Post is supposed to serve as an example of good practice then the first example (A) would be better -- and also far more clear -- as,

restart;
with(ScientificConstants):

GetValue(Constant(g));

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instead of its current (and muddled) form, ie.

restart;
with(ScientificConstants):

ScientificConstants:-GetValue(Constant(g))

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Also, the Help page with Topic UsingPackages could be improved in several ways. It's an important usage page for new users, and ought to be a paragon of lucidity and helpfulness.

- It should utilize the colon-dash syntax, eg. P:-E, and not the square-bracketed, indexed syntax, P[E], in its early examples. The latter form is inferior because it can sometimes need the extra safety of having the index-name to be uneval-quoted like P['E'] (as mentioned later in that very page!). In fact the indexed form can sometimes need to be P[':-E'], which appears silly since P:-E is safer and simpler.

It's not helpful or sensible for that Help page to first describe examples using the inferior P[E] form, and only in a later paragraph mention that the P:-E form is more recommended.

The indexed form like P[E] should only appear in a very late paragraph on that Help page, on account of there being a relatively small number of old packages not converted to work with the recommended colon-dash P:-E form.

- That Help page is too verbose and abstract. A few sensible, concrete (actual) examples would be better and more understandable that all that abstract talk of some PackageName. New users shouldn't have to decode all that, including the abstract PackageName['command'](arguments).

- After the basic examples of short and long form have been demonstrated with nice clean, clear, and concrete examples then a couple of examples of the (underdocumented!) uses and use syntax would be relevant and completely apropos. For example,

restart;
use ScientificConstants in
  GetValue(Constant(g));
end use;
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restart;
G := proc()
  uses ScientificConstants;
  GetValue(Constant(g));
end proc:

G();
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And, to be helpful to the programmer:

restart;
use SC=ScientificConstants in
  SC:-GetValue(SC:-Constant(g));
end use;
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restart;
F := proc()
  uses SC=ScientificConstants;
  SC:-GetValue(SC:-Constant(g));
end proc:

F();
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How many roots do you need to find?

Please stop posting duplicates and close followups of this in separate Question threads.

Instead, please put your followup queries or additional details here.

@hisabt How is this any different from what Tom answered, earlier?

@Tamour_Zubair The problem with downloading is caused by the presence of the # special character in your file's name.

I fixed the link of such an example in another Question, yesterday. I don't want to make that a habit. Perhaps you could use another filename.

@tomleslie I've fixed the link.