@dharr You need to replace forget(Int) with forget(evalf).

@acer Why did you use unevaluation quotes around util rather than making it a procedure?

Yes, I also don't like these extra brackets. They are very common around derivatives, for example diff(f(x),x)^2 becoming (diff(f(x),x))^2, even when that is transcribed from 2D into plaintext code. I spend too much time editing them out. 

Oddly enough, the extra brackets don't occur if you change your example from subtraction to addition.

@lemelinm You original Question very clearly and explicitly (in at least 5 different places, including the title and supplied image) asked about variables with assumptions. Now you say, essentially, that you want information about variables with assignments, which are mutally exclusive from variables with assumptions. (I am just explaining the source of my understanding of the Question, not trying to criticize you.)

The variables that have been assigned by you in the current session can be obtained by anames(user). To get them as a table, you could use

MyVars:= 'MyVars':
MyVars:= table((evaln=eval)~([anames](user)));

With a small amount of extra work, that table could be formatted; but you'd need to be careful about variables whose values are too large to easily display.

@C_R The ~ isn't needed to make the `*` case work. What's shown is just a red herring. See my Answer for complete details.

@janhardo You wrote (Replying to @dharr ):

• I'm not a fan of your code, which only shows maple commands. Keep in mind, that someone is asking for your help and needs some more explanation.

I doubt that the OP needs any mathematical help with this. You can view the OP's other Questions to assess this. I think that only help with the Maple commands is needed.

So, what's your theorem, or the featured item in your paper? Is it that the maximal gap for odd primes p and q is min(p, q) - 1?

@Alfred_F I don't know if you consider the following to be a "trick", but it certainly still needs to be done to complete @mmcdara 's solution: Generate the 2nd initial condition. It can be done like this:

IC_2:= eval[recurse](convert(eq, D), {x= 0, IC});
                                        3
                      IC_2 := D(y)(0) = -
                                        2

@Ronan The Beta Forum is a forum for beta testers of the next-to-be-released version of Maple. See https://beta.maplesoft.com/welcome/ and https://beta.maplesoft.com/about/

One needs to apply and be approved to get access. Details are on the above web pages.

While cleaning up that worksheet for posting, I accidentally deleted a line of code. (I need to acquire the habit of always doing "Execute entire worksheet" before posting.) The corrected worksheet is now above.

@WA573 I think that the command that you want is VariationalCalculus:-EulerLagrange.

@C_R You might not realize that you are a Moderator, and thus you can read the deleted content by attempting to Edit it. If you do that, you will see that all 12 of those deleted Answers are pure spam: advertising for something related to the game Minecraft. The vast majority of moderator-deleted content is spam, as you can verify.

I don't think most readers here realize the huge amount of spam that I and other Moderators delete every day. By "spam" I mean strictly unsolicited advertising for products and services that have absolutely nothing to do with Maple or math. I never use the word to refer to any other type of low-quality, inappropriate, or repetitive writing, no matter how much I think it should be deleted.

@dharr It's a shame that some of Maple's integer-arithmetic commands (such as isqrt and iroot) return the closest value rather than the floor. I've been computer programming for 46 years. When doing exact integer arithmetic, I almost always want the floor, I occasionally want the ceil, and I've absolutely never had an application where I wanted the closest value. So, every time I use iroot or isqrt, I need to adjust the result.

Can anyone recall ever wanting the closest exact-integer value?

Is an annulus allowed as one (or more) of the parts? Or are only topological homeomorphs of a disk allowed? If annuli are allowed, is their circumference defined to be the sum of the circumferences of their inner and outer circles? 

@dharr I just posted a corrected Answer. Although I could've used shape= hermitian, this didn't seem to make any noticeable improvement in the Eigenvectors performance.