You can read in a technical report about the theoretical background.
Some more publications are in work.
The basic idea is to map a planning problem represented as an entailment problem in the fluent calculus , which is a way to specify action and change problems in first order logic, to propositional logic in a way that a plan, if one exists, can be reconstructed from models of the propositional formulae. These formulae are represented by BDDs and are recursively calculated by means of BDDs. The process is repeated, until the set of goal states is met. If there is no plan then it is able to prove there isn't one. It is able to reuse its results to generate many solutions for the planning problem or a subset of its results for planning problems with different initial state but equal transition relation.