Something a little more prosaic after the last set of messages on mit-scheme-devel. Just to get a feel for the speed and stability of a new system I run a long Fibonacci recursive functioning and I must have mixed up an old version which was much faster, (fib 42) -> 3s instead of 25s, and the only difference seems to be the following if statement.
(if (<= n 2) 1 (fib……. (if (or (= n 1) (= n 2) 1 (fib……… Is the underlying code so different?