hello in clips i have this template: (deftemplate cell(slot x)(slot y)(slot alive)) and this fact : (start 1 1) then i have this claus in the LHS : ?start<-(start ?x ?y) and i want to get the variable ?a1 (cell (x (+ ?x 1) )(y ?y)(alive ?a1)) it seems that it's not allowed to add to the variable "(+ ?x 1)" so how can i achive what i want.