First see ../../README.

In this directory, BinaryTries.hs illustrates properties quantified
over functions and requiring the unique existence of a data-structure.
Two different trie representations are defined for sets of bitstrings.
The properties state that each set has a unique representation as a
trie -- true for the second representation, but not for the first.
The properties are specified using functions with boolean results
as a pure representation of sets, independent of any data structure.
Compile or interpret BinaryTries.main for the self-introducing tests.