Hello schemers, the procedure (rationalize x1 x2) from (rnrs) takes a number x1 and returns the simplest rational that doesn't differ from x1 by more than x2. The implementation in guile has this behavior: scheme@(guile-user)> (rationalize #e-0.67 1/4) $1 = -2/3 The problem here is that -1/2 is simpler than -2/3 (since 1<2 and 2<3) and it also doesn't differ from #e-0.67 by more than 1/4 (even though the difference is larger than for -2/3, it is still less than 1/4). So the result from the expression above should be -1/2. Tested with Guile 2.0.9.40-824b-dirty. Regards, -- Göran Weinholt "On your own and though you feel alone you are alive. Don't you know it's just another day." -- You Are Alive, Fragma