On Monday 20 October 2008 10:53:59 Aubrey Jaffer wrote: > | From: Ken Dickey <[EMAIL PROTECTED]> ... > | For me, < is a test for a _relationship between numbers_ (which can be > | extended transitively). > > Just as + and * are operations on numbers, but r4rs...r6rs define + > and * for 0 and 1 argument cases. > > In SCM and Guile, (<) is #t.
[And in Gambit, but there are many Scheme implementations that give an error]. I accept that there is a well defined base case (identity) for * and + . I find it wacky but perhaps useful that (gcd) ==> 0 . I accept that returning #t for relational tests on zero and one argument cases operationally may make some code more compact. I don't see how it helps me reason. I fail to see a model or proof that would sensible be helped by having the unrelated empty sequence or sequence of one element compare <, >, and = . It seems somehow too close to "assume black is white, not prove you are the pope" kind of logic. Is (and (< -inf.0) (> +inf.0)) => t# really helpful to clarity of thought? I am happy to be educated here. I am still looking for a model which makes sense to me [and which I can explain to a student who's background is high school mathematics]. Cheers, -KenD _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
