It is very unlikely that something would be fixed for Maple 16 now that Maple 17 has been released. But we might as well see if the error is also produced in Maple 17, so upload your program.

And, are you sure that the results that Maple 14 and 15 give are correct? There's a chance (perhaps small) that an error message is the correct response to your problem, and represents the correction of a bug rather than the introduction of one.

Also a nice trick. This shows that any distinct region can be selected if you can "trace" the border as one continuous path.

Also a nice trick. This shows that any distinct region can be selected if you can "trace" the border as one continuous path.

Try 7/2. I get a Beta function in Maple 17.

Does this line have a typo?

X := : Y := Matrix(2): Z := Matrix(2):

Or is there some new syntax that I'm not aware of?

Does this line have a typo?

X := : Y := Matrix(2): Z := Matrix(2):

Or is there some new syntax that I'm not aware of?

Nice trick with the color= white. A variation is to add the option transparency= 0 to the second plot.

Nice trick with the color= white. A variation is to add the option transparency= 0 to the second plot.

@JamesK 

I know:P.....I've also tried Tree := Tree, {whattype(expr)},{whattype(elem)}; but I get the same error...what can I do?

A set cannot have two copies of the same element. But you can make a copy of a symbol which looks the same but is essentially different. You do this with convert(..., `local`). Example

{A,A};
                              {A}
b:= convert(A, `local`);
                               A
{A,b};
                             {A, A}

You can make any number of copies this way. A string cannot be copied like this. This is why I labeled the vertices with symbols instead of strings in my FunctionToTree.

@JamesK 

I know:P.....I've also tried Tree := Tree, {whattype(expr)},{whattype(elem)}; but I get the same error...what can I do?

A set cannot have two copies of the same element. But you can make a copy of a symbol which looks the same but is essentially different. You do this with convert(..., `local`). Example

{A,A};
                              {A}
b:= convert(A, `local`);
                               A
{A,b};
                             {A, A}

You can make any number of copies this way. A string cannot be copied like this. This is why I labeled the vertices with symbols instead of strings in my FunctionToTree.

@JamesK I see....What do you recommend I should do?

To answer that simplistically: Anything can be converted to a string with convert(..., string) or sprintf("%a", ...); anything can be converted to a symbol with convert(..., symbol) or nprintf("%a", ...).

But since I know where you're going with this, I suggest that you study closely my FunctionToTree module in the other recent thread here. You're going to encounter exactly the same problems that I did when writing that, even though you're not first applying ToInert.

@JamesK I see....What do you recommend I should do?

To answer that simplistically: Anything can be converted to a string with convert(..., string) or sprintf("%a", ...); anything can be converted to a symbol with convert(..., symbol) or nprintf("%a", ...).

But since I know where you're going with this, I suggest that you study closely my FunctionToTree module in the other recent thread here. You're going to encounter exactly the same problems that I did when writing that, even though you're not first applying ToInert.

@JamesK 

I replaced Tree := Tree, {whattype(elem),elem} with Tree := Tree, {whattype(elem)} and I get the following output and error :

Error, (in GraphTheory:-Graph) invalid edge/arc: {2}

Well, of course. Every edge needs two vertices.

@JamesK 

I replaced Tree := Tree, {whattype(elem),elem} with Tree := Tree, {whattype(elem)} and I get the following output and error :

Error, (in GraphTheory:-Graph) invalid edge/arc: {2}

Well, of course. Every edge needs two vertices.

@STHence 

Is there any way that Maple only solves first 9 equations and then substitutes the resluts to the last equation at each instant? 

Like I said, I already did solve it for only the first 9 equations. Doing so, each "instant" would take on the order of 53 minutes of CPU time. So if the integration uses, say, 200 evaluation points, then that could take a week or more. (Although there may be a "learning" effect where subsequent evaluation points take less time.)

Update: In addition, without last ODE, by using "eliminate" function in order to remove lambda 1 and lambda 2 from the equations, Maple can solve first 9 ODEs without any errors or warning.

Like I said, the dsolve itself ran fine in 22 seconds. It is using the results of the dsolve that takes a lot of time.

There's a chance that increasing the error tolerances and settings Digits to, say, 4 will make it run significantly faster. I don't have much hope for this approach though. It might be possible to simplify the equations after the eliminate and before the dsolve. And it might be possible to apply a code optimizer like codegen[optimize] to the procedure that dsolve returns.