08.2 Inference in First Order Logic| Resolution

Question 1

Conjunctive Normal Form for First-Order Logic
Conjunctive normal form is identical to the one in propositional logic, except that …

Give an example

Answer 1

literals are allowed to be universally quantified variables.

Example
∀x ,∀y ,∀z
American(x) ∧ Weapon(y) ∧ Sells(x,y,z) ∧ Hostile(z) ⇒ Criminal(x)
can be written in CNF using implication elimination and De Morgan as
∀x ,∀y ,∀z ¬American(x)∨¬Weapon(y)∨¬Sells(x,y,z)∨¬Hostile(z)∨Criminal(x)

Question 2

Conversion to CNF

Answer 2

See slides 53/54/55/56 –> do it on paper