@Muhammad Ali 

I am using Maple 18.00 / 64 on Windows 8.1 / 64.

@wenny Why not just take the advice of the error message and simply change {u1 > 40, u2 > 30} to {u1 >= 40, u2 >= 30}?

@Kitonum

Kitonum: I, and others on MaplePrimes, have told you on numerous occasions that in Maple it is extremely inefficient to build a list (or set) by adding elements one at a time to an existing list (or set). Yet you continue to do it often. While it is not always possible to avoid the need to add the elements one at a time, it is always possible to avoid adding them to a list or set by adding them to a table or Vector and converting to a list or set when you're done adding. Observe:

List_by_op:= proc(n::posint)
local i, L:= []:
     for i to n do L:= [op(L), i] end do
end proc:

List_by_table:= proc(n)
local i, L:
     for i to n do L[i]:= i end do;
     convert(L, list)
end proc:

List_by_Vector:= proc(n)
local i, L:= Vector(0):
     for i to n do L(i):= i end do;
     convert(L, list)
end proc:

time(List_by_op(2^15));
     5.616

time(List_by_table(2^15));
     0.093

time(List_by_Vector(2^15));
     0.046

@Kitonum 

But the desired output is, I believe,

Your procedure is the inverse function of the desired procedure.

@Alejandro Jakubi 

So, if you are at this situation, the most efficient usage of your RAM resources is using the CLI as much as possible.

Or not displaying large results, including plots with a large number of data points and animations with a large number of frames. Plots can be sent to a separate window.

@Markiyan Hirnyk 

Vote up is mine.

I can't find documentation for the option domain= real. Do you know where I can find that?

What happens for you when you try the solve command that you posted? For me, it works, producing a medium-length answer (about 5 screens full).

@casperyc Have you ever clicked on that "Your Contributions" and gotten it to work? It has never worked for me.

Do you have any initial conditions?

@oldstudent As far as I can tell, the Replies aren't even indexed by Google.

@Markiyan Hirnyk Kitonum is considering the range 000 to 999, not 1 to 1000, when he makes the statement about the equality of all digits. Now clearly the latter range has the same number of 5s as the former, although the number of 1s and 0s is different.

Could you be more specific?

@tomet Two ideas come to mind. The first is a logarithmic plot. The second is restricting the z-axis. You restrict the z axis with something like

plot3d(..., view= [DEFAULT, DEFAULT, 0..100]);

@Muhammad Ali I need more details about your project with the nested `if` commands. I am sure that it can be done, but it will require some thought.

As for your seq question, just do it as

seq([command1, command2]), i= 1..n);

@Muhammad Ali You can nest them however you want. It only checks the conditions that it needs to check. The following proves it:

P:= proc() print("Here."); true end proc:
`if`(P(), A, `if`(P(), B, C));
                        
                            "Here."
                               A
Note that "Here." is only printed once. The second P() is never evaluated.

Also, you should look into using the andmap and ormap commands, both of which only evaluate the boolean conditions that they need to:

ormap(P, [1,1]);

                            "Here."
                              true