Added map_a.
Cleaned whitespace.
Cleaned whitespace and changed unique to take (=) by default.
Cleaned whitespace and changed unique to take (=) by default.
Add error and continuation monads. Add modify in state. Fix naming of sum, msum and lsum. Add strict version of transpose. Change unique to take (=) by default.
Add documentation and modifications consistent with those of monad.ml.
Fix whitespace.
Add documentation.