Resolution: brief summary
l Full first-order version:
l1 ··· lk,          m1 ··· mn
(l1 ··· li-1 li+1 ··· lk m1 ··· mj-1 mj+1 ··· mn
   where Unify(li, mj) = θ.
l The two clauses are assumed to be standardized apart so that they
share no variables.
l For example,
Rich(x) Unhappy(x)
                  Rich(Ken)
Unhappy(Ken)
   with θ = {x/Ken}
l Apply resolution steps to CNF(KB α); complete for FOL