Back to notes -- Keyboard shortcut: 'u'        next -- Keyboard shortcut: 'n'  Slide program -- Keyboard shortcut: 't'    A naive attempt to define a recursive function.Lecture 2 - slide 10 : 35
Program 1
(let ((fac
         (lambda (n)
            (if (= n 1)
                1
                (* n (fac  (- n 1)))))))
  (fac 5)
)

; reference to undefined identifier: fac