University of Washington • CSE583 • D. Notkin © 2000
11
Another example
l(define (fact n)
  (if (<= n 0)
      1
      (* n (fact (- n 1)))))
fact   
l(fact 20)
2432902008176640000
l(fact 1)
1
l(fact “xyz”)
???
lEverything is an expression, including what we usually think of as control structures lPrefix operators and functions calls are regular, although not traditional