Hello schemers, one property of the flonum procedures in r6rs is that they return flonums. This should not happen: scheme@(guile-user)> (import (rnrs)) scheme@(guile-user)> (fllog -1.0) $1 = 0.0+3.141592653589793i scheme@(guile-user)> (flsqrt -1.0) $2 = 0.0+1.0i scheme@(guile-user)> (flasin 3.0) $3 = 1.5707963267948966-1.762747174039086i scheme@(guile-user)> (flacos 3.0) $4 = 0.0+1.762747174039086i scheme@(guile-user)> (flexpt -1.0 0.5) $5 = 6.123031769111886e-17+1.0i These results are not flonums. In r6rs-lib it says "the result may be a NaN or some unspecified flonum." So returning +nan.0 would be better. Tested with Guile 2.0.9.22-7e816-dirty. Regards, -- Göran Weinholt "Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality." -- Nikola Tesla