Quantified Boolean formula (QBF) techniques are used in determining QBF
satisfiability. A QBF is broken into component parts that are analyzable
by a satisfiability (SAT) solver. Each component is then independently,
and perhaps in parallel, analyzed for satisfiability. If a component is
unsatisfiable, then it is determined that the QBF is unsatisfiable, and
the analysis is stopped. If a component is satisfiable, then an
assignment corresponding to the satisfiable component is noted. If a
component is satisfiable, then it is appended to another untested
component to provide a combination component, and the satisfiability of
the combination component is analyzed. Such appending and analysis is
repeated until the QBF is completed and determined to be satisfiable or
determined to be unsatisfiable.