> Since Guile now supports exact rationals, shouldn't it return an exact result?
I actually agree with you (I implemented rationalize in Guile, and originally it always returned a ratio -- why else call it "rationalize"?), but Marius pointed out that R5RS says "With the exception of inexact->exact, the operations described in this section must generally return inexact results when given any inexact arguments" in the section including rationalize. I doubt that R6RS fixed this bug. So, to get an exact result you need to give exact arguments: guile> (rationalize (inexact->exact .33) 1/10) 1/3
