Examples:
Election and prognoses
generalize fixed Dist to (Distribution prob) whereever possible
Use pretty printer in PrintList? Which one?
current pretty function is nice for single Dist values,
but not for (Dist a, Dist b) et.al.
Collection.draw using StateT
QuickCheck properties
use a non-empty list structure for the distribution
generalize ToFloat class to Num
Need for multi-parameter type classes?
create export list
new data type for continuous distributions:
C (Float -> Float)
prove correctness of >>=? (What did Martin mean with this comment?)