o introduced <, >, ≥ in the grammar
o added lambda to the possible binders
o added a range expression to binders
Introduced monadic traversal of trees
refactored continuous to use the StateT monad transformer instead of
threading program arguments and proof obligations through all the
functions.

Additionally, the cyclic executive has been factored into a
parameterized fonction.
Added the Z3.Lambda module that handles de-lambda-ification. The
creation of canonical lambda expressions now works
clean up of the code of continuous.hs