You can simulate how the functions work by loading the package and setting the security content.
Here the variable $$var
is assigned to the value "5+7"
; note that the value is a string.
evaluates, all occurrences of $$var
are replaced by its interpreted value.
If the input value cannot be interpreted, an MSPException
If the input value does not pass the security test, an MSPException
Input can also be given in MathML.