Maple 16 won't recognize VS 2012 in the Windows registry.  Instead, within Maple, execute:

Compiler:-Setup()

and point to the C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\x86_amd64\vcvarsx86_amd64 file.  You'll have to restart Maple for the change to take effect.

To place the cursor in "overscript" mode (in 2-D math), press the Ctrl + Shift + "  key combo.

If it's only a matter of showing your work to others, exporting the Maple worksheet to a PDF document is an option.

evalf(Int(...)) invokes the numerical integration routines (i.e. capitalize the "i" in int). 

There are two things you can try.

1.  You probably have hardware acceleration enabled.  You can try updating your graphics driver and see if this helps.

2.  You can enable software rendering.   To do this:

         i.  Edit the <Maple13>/bin/maple script.  Uncomment the lines

                 #USE_SOFTWARE_GL=1

                 #export USE_SOFTWARE_GL

         ii.  Go to Tools -> Options and uncheck the hardware acceleration checkbox

     The thing is that you may need some updated graphics library files for Maple 13.   If you contact support@maplesoft.com, they should be able to help you with that.

If by "accident" you mean inadvertedly pressing the <Enter> key and the whole worksheet subsequently executes, are you perhaps inserting all your Maple code under one execution group?  Some users have a tendency to do this and it's probably not the best thing to do from a best practices point of view.  Each Maple command should be inserted into its own execution group (except for those cases, like loops and condition statements, which would require a single execution group).

Hi Diemer,

Try sending an example worksheet to support@maplesoft.com.  They can investigate the issue and may be able to offer a solution.

Are you using  'Int'  (i.e. with a capital "I") along with the evalf command?  This will invoke the numerical routines.  Alternatively, you can use int(..., numeric=true) if you're using at least Maple 13.

http://www.maplesoft.com/support/help/Maple/view.aspx?path=evalf/Int

I think the sort command is what you're after.

It looks like this is a bug with 2-D math.  If you convert the last entry to 1-D math (highlight it, right-click and select "2-D Math -> Convert To -> 1-D Math Input") and change

   (3*Unit('`k&Omega;`')*5)*Unit('A');

to

   (3*Unit('Omega')*5)*Unit('A');

it will work.