If you are using the MuPad symbolic engine from Symbolic Toolbox (R2008b) or higher, you can use the ASSUME function from MuPad as follows:
syms x
evalin(symengine,'assume(x,Type::Integer)')
To remove assumptions from the variable x, you can use the following command:
syms x clear
If you are using Symbolic Toolbox (R2008a) or before, you will also need the Extended Symbolic Toolbox to do this. The Maple function ASSUME allows you to add assumptions to a symbolic variable. The following example demostrates the creation of a symbolic integer variable:
syms x
maple('assume(x,integer)');
