Bug fix: The <= and >= procedures now return false for NaN inputs; they
previously returned true.  Additionally, on amd64, all of the numerical
comparison routines now raise floating-point exceptions for NaN inputs
according to the rules of IEEE 754-2008, which can be tested and can
trap.  (The new procedures flo:safe<, flo:safe<= flo:safe>, flo:safe>=,
flo:safe=, flo:safe<>, and flo:unordered? avoid exceptions.)

(The i386 compiler back end does not correctly raise floating-point
exceptions, and the C and SVM back ends may or may not depending on
your C compiler's IEEE 754-2008 conformance.)
