On Oct 21, 2008, at 8:03 AM, Ken Dickey wrote: > Doesn't it make more sense to require existence for comparison?
Existence of one ordered pair does not matter much. You need to either prove the existence of a counter example to produce #f, or to prove universality (e.g., with for-all) to produce #t. You can't say: I'll require that all adjacent pairs are ordered, except when there are no pairs, where I'll switch my logic and demand the existence of an ordered pair. > (define (monotonic? ordered? sequence) > (let ( [list-of-pairs (pairs-in sequence)] ) > (if (null? list-of-pairs) > #f > (for-all > (lambda (pair) (ordered? (car pair) (cdr pair))) > list-of-pairs)) > ) ) You just made an arbitrary exception to the rule by providing an arbitrary value for the (null? ---) case. I don't see that following your rule of least surprise. Aziz,,, _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
