What is Resolution principle in artificial intelligence?

Answer 1

Resolution

Robinson in 1965 introduced the resolution principle, which can be directly

applied to any set of clauses. The principal is

"Given any two clauses A and B, if there is a literal P1 in A which has a

complementary literal P2 in B, delete P1 & P2 from A and B and construct a

disjunction of the remaining clauses. The clause so constructed is called

resolvent of A and B."

For example, consider the following clauses

A: P V Q V R

B: `p V Q V R

C: `Q V R

Clause A has the literal P which is complementary to `P in B. Hence both of

them deleted and a resolvent (disjunction of A and B after the complementary

clauses are removed) is generated. That resolvent has again a literal Q whose

negation is available in C. Hence resolving those two, one has the final

resolvent.

A: P V Q V R (given in the problem)

B: `p V Q V (given in the problem)

D: Q V R (resolvent of A and B)

C: `Q V R (given in the problem)

E: R (resolvent of C and D)