>> (if (if 3 4 5) a b) 
|(eval-expression
   (if-exp (if-exp (lit-exp 3) (lit-exp 4) (lit-exp 5)) (var-exp a) (var-exp b))
   (halt-cont)
   (((a b) . #2(3 4))))
|(eval-expression
   (if-exp (lit-exp 3) (lit-exp 4) (lit-exp 5))
   (if-cont (var-exp a) (var-exp b) (halt-cont) (((a b) . #2(3 4))))
   (((a b) . #2(3 4))))
|(eval-expression
   (lit-exp 3)
   (if-cont
     (lit-exp 4)
     (lit-exp 5)
     (if-cont (var-exp a) (var-exp b) (halt-cont) (((a b) . #2(3 4))))
     (((a b) . #2(3 4))))
   (((a b) . #2(3 4))))
|(apply-cont
   (if-cont
     (lit-exp 4)
     (lit-exp 5)
     (if-cont (var-exp a) (var-exp b) (halt-cont) (((a b) . #2(3 4))))
     (((a b) . #2(3 4))))
   3)
|(eval-expression
   (lit-exp 4)
   (if-cont (var-exp a) (var-exp b) (halt-cont) (((a b) . #2(3 4))))
   (((a b) . #2(3 4))))
|(apply-cont
   (if-cont (var-exp a) (var-exp b) (halt-cont) (((a b) . #2(3 4))))
   4)
|(eval-expression (var-exp a) (halt-cont) (((a b) . #2(3 4))))
|(apply-cont (halt-cont) 3)
3
|#<void>
#<void>
>>