Integer instances and arithmetic

I am trying to create instances of type integer and increment these 
instances by some amount.

I have found a work around to do this but would be very appreciative
for a simpler solution if one exists or pointers to Powerloom features I 
am overlooking.

I found that I could not accomplish defining an integer instance with 
"(assert (INTEGER x))".
I am using the following workaround:

(deffunction intVar ((?x thing)) :-> (?y integer)) .

I also have a need to increment an integer instance by some amount.

I found that:
(assert (=(intVar g) 0))
(assert (=(intVar g) (+ (intVar g) 1)))

will not map "g" to "1" .

I am instead incrementing "g" by executing:

(assert-from-query
(retrieve all (+ (intVar g) 1 ?x))
:pattern
(setofall (?x Integer) (=(intVar g) ?x) ) )

Thanks for your help and time.
Lee Martie
[email protected]