@Michael 

Maple 15 still brings Classic GUI under Windows or Linux. From readme.txt:

Starting Classic Worksheet Maple 15
Select Start > Programs > Maple 15, and then Classic Worksheet Maple 15.

@Michael 

Maple 15 still brings Classic GUI under Windows or Linux. From readme.txt:

Starting Classic Worksheet Maple 15
Select Start > Programs > Maple 15, and then Classic Worksheet Maple 15.

@acer 

I have the impression that search for a word only looks at titles and labels.

@Christopher2222 

Indeed, just bringing back to surface those forgotten threads from while to while. It would be healthier than some pills for Patrick's memory...

For the record, the couple of people were Christopher2222 and hyrnick. I would suggest abraham to spam more often those threads on the bright side of spamming :)

@Alec Mihailovs 

In Maple 15 it is even worst: only the undefined first term is returned...

Apparently the problem (or part of it) has the same origin as your previous example. 

In Maple 15:

kernelopts(opaquemodules=false):
SumTools:-DefiniteSum:-IndefFirst:-MainInfinite((-1)^x/(x^n), x, 1, infinity) assuming n>1;
                                 FAIL

SumTools:-DefiniteSum:-IndefFirst:-MainInfinite(1/(k^5+1), x, 1, infinity);

                               infinity
                            --------------
                                    5
                            signum(k  + 1)

While in Maple 14.01:

kernelopts(opaquemodules=false):
SumTools:-DefiniteSum:-IndefFirst:-MainInfinite((-1)^x/(x^n), x, 1, infinity) assuming n>1;
                          (1 - n)
                        (2        - 1) Zeta(n)

SumTools:-DefiniteSum:-IndefFirst:-MainInfinite(1/(k^5+1), x, 1, infinity);

                          infinity        1
                       -------------- - ------
                               5         5
                       signum(k  + 1)   k  + 1

@Alec Mihailovs 

In Maple 15 it is even worst: only the undefined first term is returned...

Apparently the problem (or part of it) has the same origin as your previous example. 

In Maple 15:

kernelopts(opaquemodules=false):
SumTools:-DefiniteSum:-IndefFirst:-MainInfinite((-1)^x/(x^n), x, 1, infinity) assuming n>1;
                                 FAIL

SumTools:-DefiniteSum:-IndefFirst:-MainInfinite(1/(k^5+1), x, 1, infinity);

                               infinity
                            --------------
                                    5
                            signum(k  + 1)

While in Maple 14.01:

kernelopts(opaquemodules=false):
SumTools:-DefiniteSum:-IndefFirst:-MainInfinite((-1)^x/(x^n), x, 1, infinity) assuming n>1;
                          (1 - n)
                        (2        - 1) Zeta(n)

SumTools:-DefiniteSum:-IndefFirst:-MainInfinite(1/(k^5+1), x, 1, infinity);

                          infinity        1
                       -------------- - ------
                               5         5
                       signum(k  + 1)   k  + 1

@Alec Mihailovs 

For this case of a numeric n it is using an explicit hypergeometric representation. The basic steps are:

`sum/hypergeom`(Sum((-1)^(x+1)/x^11,x = 1 .. infinity));
  hypergeom([1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
        [2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2], -1)

convert(%,StandardFunctions);

                            1023
                            ---- Zeta(11)
                            1024

There is even more fun for the case of the change of sign when n is symbolic: it involves a regression in Maple 15:

kernelopts(version);
sum((-1)^k/k^n,k=1..infinity) assuming n>1;
       Maple 15.00, IBM INTEL NT, Mar 20 2011, Build ID 582305

                            infinity
                             -----       k
                              \      (-1)
                               )     -----
                              /        n
                             -----    k
                             k = 1

Now it is consistent, isn't it?

@Alec Mihailovs 

For this case of a numeric n it is using an explicit hypergeometric representation. The basic steps are:

`sum/hypergeom`(Sum((-1)^(x+1)/x^11,x = 1 .. infinity));
  hypergeom([1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
        [2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2], -1)

convert(%,StandardFunctions);

                            1023
                            ---- Zeta(11)
                            1024

There is even more fun for the case of the change of sign when n is symbolic: it involves a regression in Maple 15:

kernelopts(version);
sum((-1)^k/k^n,k=1..infinity) assuming n>1;
       Maple 15.00, IBM INTEL NT, Mar 20 2011, Build ID 582305

                            infinity
                             -----       k
                              \      (-1)
                               )     -----
                              /        n
                             -----    k
                             k = 1

Now it is consistent, isn't it?

@Alec Mihailovs 

May be just that such a transformation (or something equivalent) is not implemented. These are the methods tried:

infolevel[SumTools:-DefiniteSum:-Definite]:=5:
sum((-1)^(k+1)/k^n,k=1..infinity) assuming n>1:

ClosedForm:   "try the front-end to compute simple definite sums"
ClosedForm:   simple definite summations
ClosedForm:   "try the method of integral representation"
ClosedForm:   "try the method of first computing the indefinite sum"
ClosedForm:   infinite summation
ClosedForm:   "try the method of converting the definite sum to hypergeometric functions"
ClosedForm:   definite summation using hypergeometric functions
ClosedForm:   definite summation using hypergeometric functions
ClosedForm:   "try the method of definite sum of hypergeometric term"
ClosedForm:   "try detecting a telescoping sum or partial sum"

@Alec Mihailovs 

May be just that such a transformation (or something equivalent) is not implemented. These are the methods tried:

infolevel[SumTools:-DefiniteSum:-Definite]:=5:
sum((-1)^(k+1)/k^n,k=1..infinity) assuming n>1:

ClosedForm:   "try the front-end to compute simple definite sums"
ClosedForm:   simple definite summations
ClosedForm:   "try the method of integral representation"
ClosedForm:   "try the method of first computing the indefinite sum"
ClosedForm:   infinite summation
ClosedForm:   "try the method of converting the definite sum to hypergeometric functions"
ClosedForm:   definite summation using hypergeometric functions
ClosedForm:   definite summation using hypergeometric functions
ClosedForm:   "try the method of definite sum of hypergeometric term"
ClosedForm:   "try detecting a telescoping sum or partial sum"

@acer 

I have looked at my archive copy of this blog. Point 6. and the last two paragraphs were the following:

6. If you want to completely hide complicated subexpression you can also do that with labels and freeze:
   f:=(31*y-53)^2*(-62*x^3+97*x^2-73*x-4)-1;
   sol:=[solve](f,x,Explicit);
   sol:=subsindets(sol, identical(%2), freeze);
   Recover the original expression with thaw(sol);
   You might do something like this if you wanted to call expand or normal on the expression without expanding the subexpression %2.

So, how do you use subexpression labeling in the GUI?  If you are using the classic worksheet interface, the answer is that you just have to change your renderer with interface(prettyprint=2):  (the default is =3: editable math -- I am not sure what functionality this has over 2 in the classic interface).  Labeling should work as it does in TTY Maple after doing this.

If you are using the Standard interface, you can also use interface(prettyprint=2): (again, I am not sure what the difference is between this and =3, but I would guess there is some functionality being lost by setting it to 2) to turn labeling on, but, unfortunately, the labels do not get assigned.  You can still do some of the cool things mentioned above, but you have to cut and paste your subexpressions. I also notice that labeling more "aggressive" here (a lot more labels are generated for the two examples above). I am guessing that the standard interface is calling a different internal routine to do the labeling.

@Alec Mihailovs 

So, the count should include those of the procedure..

@Alec Mihailovs 

In practice, three lines as a substitution is needed like:

f:=sin(x)+sin(y):
subs(x=u+v,y=u-v,f):
eval(%=expand(%),solve({u+v=x,u-v=y},{u,v}));

For an expression f long and complex enough, you won't replace by hand each occurrence of x and y with u+v and u-v . Actually, more subtle and customized substitutions would be needed because a general one as the one above will produce frequently unwanted expansions as here:

f:=exp(x)*(sin(x)+sin(y)):
subs(x=u+v,y=u-v,f):
eval(%=expand(%),solve({u+v=x,u-v=y},{u,v}));

  exp(x) (sin(x) + sin(y)) =

        2 exp(x/2 + y/2) exp(x/2 - y/2) sin(x/2 + y/2) cos(x/2 - y/2)

@Alec Mihailovs 

I do use email and receive notifications (I am very old-fashioned!). Their behavior in primes 2 is odd in multiple ways. I have not reported on that as there are much more urgent unsolved problems. Email notifications were more useful in primes 1 (when they worked). So, in this area, there was also a downgrade, in my opinion.

Feeds, introduced in primes 2, are the single feature that I consider an improvement.