R7RS-small Appendix B says:

exact-closed
All algebraic operations except / produce exact values
given exact inputs.

Frankly, this seems weird.  I would expect / to give exact values
given exact inputs if an implementation has this property.

Wikipedia defines "Algebraic operation" to include "taking roots".
I would expect few if any implementations to produce exact values
given exact inputs to sqrt or non-integer 2nd argument to expt.

I didn't find this covered in the Errata.

Should it be the following instead?
   All algebraic operations except sqrt or expt produce exact values
given exact inputs.

Or better:
   The algebraic operations +, -, *, / (assuming the second argument is non-zero),
   and expt (assuming the second argument is an integer) all produce exact values
   given exact inputs.
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/

_______________________________________________
Scheme-reports mailing list
Scheme-reports@scheme-reports.org
http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports