1.Example of Knowledge Base

2.Knowledge Base: example According to American Law, selling weapons to a hostile nation is a crime The state of Nono , is an enemy, it has some missiles All missiles were sold to Nono by colonel West, who is an American Proof that colonel West is a criminal

3.Knowledge Base: . . . Selling weapons to a hostile nation by an American is a crime: American(x ) ^ Weapon (y) ^ Sells (x , y, z ) ^ Hostile (z )  Criminal(x) Nono . . . Has some missiles, i.e. Exists x Owns( Nono , x) ^Missile(x): Owns( Nono , M1 ) ^ Missile(M1) . . . All missiles were sold to Nono by colonel West ForAll x Missile(x) ^ Owns( Nono , x)  Sells(West, x , Nono ) Missiles are weapons: Missile(x)  Weapon(x) Enemy of America is Hostile : Enemy(x , America )  Hostile(x) West, is an American. . . American(West) State Nono , is an enemy of America.. . . Enemy( Nono , America )

4.Forward Chaining: example

5.Forward Chaining: example

6.Forward Chaining: example

7.Backward Chaining: example

8.Backward Chaining: example

9.Backward Chaining: example

10.Backward Chaining: example

11.Backward Chaining: example

12.Backward Chaining: example

13.Backward Chaining: example

14.Resolution: example