user=> (< Float/NaN 1.0)
false
user=> (<= Float/NaN 1.0)
true
Both comparisons should yield false. It seems that (<= x y) is
implemented by negating the result of (< y x), which is fine for
totally-ordered sets, but unfortunately IEEE 754 floating-point
numbers do not form such a set. (See e.g. Java Language Specification
§15.20.1).