muZ: routines related to solving satisfiability of Horn clauses and 
solving Datalog programs.

- base - contains base routines and the main context for
         maintaining fixedpoint solvers
- transforms - common rule transformations
- rel - relational algebra based Datalog engine
- pdr - PDR based Horn clause solver
- clp - Dart/Symbolic execution-based solver
- tab - Tabulation based solver
- bmc - Bounded model checking based solver
- fp  - main exported routines
