If the return value of the function is of a simple type (e.g. numbers, symbols, etc.), then the output template is simply "some expression of that type". For example,
;; sum-of-squares: number number => number (define (sum-of-squares num1 num2) numeric-expression)In this case, an output template may not be particularly informative, but at least it reminds you that whatever expression you put in the body of the function must return type number.