Detecting CMD.EXE

From a batch file, you can determine if CMD.EXE or Take Command is loaded 
by testing for the variable function @EVAL, with a test like this: 

        if "%@eval[2 + 2]%" == "4" echo CMD.EXE is loaded!

This test can never succeed in CMD.EXE.  Other variable functions could be 
used for the same purpose.