+
+ratioPrec, ratioPrec1 :: Int
+ratioPrec = 7 -- Precedence of ':%' constructor
+ratioPrec1 = ratioPrec + 1
+
+infinity, notANumber :: Rational
+infinity = 1 :% 0
+notANumber = 0 :% 0
+
+-- Use :%, not % for Inf/NaN; the latter would
+-- immediately lead to a runtime error, because it normalises.