http://lonsing.github.io/depqbf/
DepQBF is a search-based solver for quantified boolean formulae (QBF)
in prenex conjunctive normal form. It is based on the DPLL algorithm
for QBF, called QDPLL, with conflict-driven clause and solution-driven
cube learning.
ClosesHomebrew/homebrew#19522.
Signed-off-by: Adam Vandenberg <flangy@gmail.com>