I am trying to see if installing Physics update package will fix a problem I am having as described here by having a fix that maybe not included in Maple 2025.2

But I do not know how to do that. When doing Physics:-Version(); or Physics:-Version(latest); Maple says

             `The "Physics Updates" package is not available for the version of Maple under development`

Does this mean Physics update package is not needed in Maple 2025.2?  Otherwise, what are the instructions to install Physics package now?

May be someone could clarify the status of Physics package and if it is something that one should still install along with SupportTools which in Maple 2025.2 was there automatically and did not need to install it.

Update 

JUst verified that Physics update package V 1881 is still needed in Maple 2025.2 as it has important fixes not merged in Maple 2025.2.

To install Physics package in Maple 2025.2 had to click on the top right corner of the worksheet (the down arrow) near the "sign in".

Then go down to "packages" and select and click on the install button next to Physics package.  (first in list).

This will download and install it.

Now closed all of Maple and restarted it.

Now Physics package V 1881 is installed and have fixes in it that are missing from Maple 2025.2.  This is why my test was failing. Now the test do not fail.

So first time, the command Physics:-Version(latest) does not work. But from now on it should work.

I would have expected all fixes made in Physics update to have been merged into the new Maple release.

In 2025.2, I found that calling Physics:-Setup causes code of `convert/diff` to change (on the fly) causing error.

I removed from my code the places I was calling Physics:-Setup explicitly, but the error still shows up. Which means there is still places in the code to cause Physics to come into play.

I just installed 2025.2 and have not done anything yet. Just running a test. 

Does one need to install Physics package?

First, let me give an example showing that calling Physics:-Setup changes `convert/diff` which ends up causing an internal Maple error

Download why_code_changes_calling_Physics_maple_2025_2_nov_24_2025.mw

Notice that now calling PDEtools:-difforder(convert(T,diff))  fail because Physics:- was called.

But my code now has no calls to Physics:-, I made sure to comment all those out. 

But I still get same error when I run my test program. Not able to find where Physics is "activated" again to cause the code change in `convert/diff` that happens dynamically when Physics is loaded.

It must be happining on different call internally. But have no idea why and where.

This is all on new PC. I have no Maple ini files or anything like this that can cause this.

Will installing Physics package explicity fixes this?   

Update

I think I know why this happens. Not all fixes made by Edgardo S. Cheb-Terrab in last Physics update are included in Maple 2025.2 !

See https://mapleprimes.com/questions/240843-Why-PDEtoolsSolve-Fail-On-This-Equation  where fix is made in Physics  v.1880 which I confirmed in Maple 2025.1.

But now I checked and this problem is back in Maple 2025.2. which means that fix was not merged into Maple 2025.2. How could this happen?

Download fixed_in_2025_1_but_missing_in_2025_2.mw

So I am hoping that figuring how to install Physics update in Maple 2025.2 will fix the current problem with convert and also bring that old fix for PDEtools:-Solve back into Maple 2025.2.

This is something that Maplesoft should have taken care of.

Update 

Figured how install Physics update package V 1881 and doing so fixed this problem in Maple 2025.2 !

This tells me that all fixes that were in Physics update package were not merged into Maple 2025.2

This worksheet shows that now code works OK, but need to make sure to install Physics update package in Maple 2025.2

Download why_code_changes_calling_Physics_maple_2025_2_nov_24_2025_V2.mw

I am finding many problems using overload in OOP.

But for starter, here is a basic one that does not use Object. Will make separate question for other issues once I figure this basic one out.

I have overload with two procs.

First proc takes 2 arguments of type string, and the second proc one argument also of type string.

When calling the overloaded proc with one argument or two arguments, it always calls the first one which takes 2 arguments.

It never calls the second, even though the call is using one argument only. It always matchs the first proc.

It seems Maple just checks if the first argument match and stops.

I also made sure to use $ for end of arguments flag.

Now when changing the order and putting as the first proc the one that take one argument and the second proc which takes two arguments, now it works. Maple calls the correct proc based on the number of arguments.

How could this be possible? Is order of procs in overload important?? How does one then figure the correct order. It should be based on match of signature of proc, not the order. i.e. match made based on number and type of arguments. 

Is there a way to make the first one work as is without having to worry about order? Or Am I making mistake somewhere?

Download why_order_makes_differenence_in_overload_nov_1_2025.mw

Solving an ode, dsolve says it used exact method and gives two solutions as result (correct result).

But when asking dsolve to solve same ode but now specifying that it uses exact method (i.e. same one it used itself before), now it gives one solution only, not two as before.

Why is that? Should not both commands give same result? i.e. two solutions?

Download why_different_solutions_maple_2025_1_oct_22_2025.mw

When solution was obtained using earlier call to solve with _EnvAllSolutions := true: set, then odetest givens internal error.

When _EnvAllSolutions := false: then no error.

Why? And is there a workaround so I can use _EnvAllSolutions := true: but have odetest still work?

Download odetest_fail_when_using_envAllsol_maple_2025_1_oct_21_2025.mw