I have a copy of Cscheme from prep.ai.mit.edu. I ran the example described: Scheme saved on Monday April 3, 1989 at 7:14:37 PM Release 6.1.2 Microcode 10.2 Runtime 13.91 SF 3.13 Student 13.3 *** Note: no graphics available in this system. *** 1 ==> (define (foo bool) (if bool (define (result) 't) (define (result) 'f)) (result)) FOO 1 ==> (foo nil) F 1 ==> (foo 't) T Am I missing something? -Tom