[r6rs-discuss] Comparison procedures' number of arguments

[Bradley Lucier]

(Puts math professor hat on ...)

In mathematics, statements about the (nonexistent) elements of the  
empty set are taken to be true; such statements are called "vacuously  
true".  "All witches are green" => #t; "all dragons are over 6 feet  
tall" => #t; "all dragons are under 6 inches tall" => #t.

In that context, all the comparison operators should return #t when  
given zero or one arguments (if an implementation wants to make that  
extension), as there are no pairs to compare.  Gambit checks to see  
that a single argument is indeed real, and throws an exception  
otherwise.

Brad