(letrec ((kernel 
          (lambda ()
            (display "Please enter a number and I'll square it: ")
            (let ((num (read)))
              (if (number? num)
                  (let ((result (* num num)))
                    ; (display "I bet you didn't know that ")
                    ; (display "Emily thinks that ")
                    (display num)
                    (display " squared is ")
                    (display result)
                    (display ".")
                    (newline))
                  (begin
                    (display "Sam thinks that you are a bit clueless today, given that ")
                    (display "you claimed that ")
                    (display num)
                    (display " is a number.")
                    (newline)
                    (kernel)))))))
  (kernel))