Numeric.Interval
data Interval a
(...)
whole
empty
null
singleton
elem
notElem
inf
sup
singular
width
midpoint
intersection
hull
bisection
magnitude
mignitude
contains
isSubsetOf
certainly
(<!)
(<=!)
(==!)
(>=!)
(>!)
possibly
(<?)
(<=?)
(==?)
(>=?)
(>?)
idouble
ifloat