[r6rs-discuss] Complex <?

[Keith Wright]

> From: Ken Dickey <Ken.Dickey at whidbey.com>
> 
> Does anyone else find it odd that
>   (< 1/3 +inf.0) => #t
> but
>   (< 1/3 +2i) ==> error "not a real number" +2i

Why are you asking this?  For what it is worth, I
do not find it odd, because +2i is, in fact, not
a real number.  (In the technical sense in which
imaginary numbers are not real (unless zero).)

> When

After the word "when" I expect to find a statement
that is satisfied by the situation to be discussed.
Instead I find a definition of unknown origin.

> (define (<? n1 n2)
>     (unless (and (number? n1) (number? n2))
>       (error '<? "arguments must be numbers" n1 n2))
>    (or (< (magnitude n1) (magnitude n2))
>          (< (angle n1) (angle n2))))

Whence this definition?

Does it bother you that (<? 1000000 +0.00001i) ==> #t?

I do not want to argue about whether the bogosity
of the defintion is essential, or a simple typo.

It is standard mathematics that the real numbers
are totally ordered by <, while the complex numbers
have no natural order.

  -- Keith