doc eq? eqv? equal?

[Kevin Ryde]

I'm looking to polish the docs for eq?, eqv? and equal? a bit.  r5rs
says numbers are unspecified for eq?, even going so far as to say

        (let ((n (+ 2 3)))
          (eq? n n))       => *unspecified*

I guess that's meant to allow something wild and strange to represent
numbers.

In guile "(eq? x x)" is always going to be true, but I'm wondering if
the docs should describe only the weaker r5rs behaviour, and advise
eqv? for anything involving numbers.