-- | 'approxRational', applied to two real fractional numbers @x@ and @epsilon@,
-- returns the simplest rational number within @epsilon@ of @x@.
--- A rational number @y@ is said to be simpler than another @y'@ if
+-- A rational number @y@ is said to be /simpler/ than another @y'@ if
--
-- * @'abs' ('numerator' y) <= 'abs' ('numerator' y')@, and
--
-- * @'denominator' y <= 'denominator' y'@.
--
--- Any real interval contains a unique simplest rational.
+-- Any real interval contains a unique simplest rational;
+-- in particular, note that @0\/1@ is the simplest rational of all.
-- Implementation details: Here, for simplicity, we assume a closed rational
-- interval. If such an interval includes at least one whole number, then