TRƯỜNG ĐẠI HỌC BÁCH KHOA TP.HCM Khoa Khoa học & Kỹ thuật Máy tính Artificial Intelligence Spring 2016 Tutorial 5 Question 1.. Doctor, Surgeon, Lawyer, Actor: Constants denoting occu
Trang 1TRƯỜNG ĐẠI HỌC BÁCH KHOA TP.HCM
Khoa Khoa học & Kỹ thuật Máy tính
Artificial Intelligence (Spring 2016)
Tutorial 5
Question 1
Given the following symbols:
Occupation(p, o) : Predicate Person p has occupation o
Customer(p1,p2): Predicate Person p1 is a customer of person p2
Boss(p1,p2): Predicate Person p1 is a boss of person p2
Doctor, Surgeon, Lawyer, Actor: Constants denoting occupations
Emily, Joe: Constants denoting people
Use these symbols to write the following assertions in first-order logic:
a Emily is either a surgeon or a lawyer
b Joe is an actor, but he also holds another job
c All surgeons are doctors
d Joe does not have a lawyer
e Emily has a boss who is a lawyer
f There exists a lawyer all of whose customers are doctors
g Every surgeon has a lawyer
Question 2
2.1 Does the fact ¬Spouse(George, Laura) follow from the facts Jim ≠ George and Spouse(Jim,
Laura)? If so, give a proof; if not, supply additional axioms as needed What happens if we use Spouse as a unary function symbol instead of a binary predicate?
2.2 Explain what is wrong with the following proposed definition of the set membership
predicate ∈ :
∀ x, s x ∈ {x|s}
∀ x, s x ∈ s ⇒ ∀ y x ∈ {y|s}
Question 3 For each pair of atomic sentences, give the most general unifier if it exists:
a P(A, B, B), P(x, y, z)
b Q(y, G(A, B)), Q(G(x, x), y)
c Older(Father(y), y), Older(Father(x), John)
d Knows(Father(y), y), Knows(x, x)
SinhVienZone.com https://fb.com/sinhvienzonevn
SinhVienZone.Com
Trang 2TRƯỜNG ĐẠI HỌC BÁCH KHOA TP.HCM
Khoa Khoa học & Kỹ thuật Máy tính
Question 4 Let L be the first-order language with a single predicate S(p, q), meaning “p shaves q.” Assume a domain of people
a Consider the sentence “There exists a person P who shaves everyone who does not shave themselves, and only people that do not shave themselves.” Express this in L
b Convert the sentence in (a) to clausal form
c Construct a resolution proof to show that the clauses in (b) are inherently inconsistent (Note: you do not need any additional axioms.)
Question 5
We have a story: “Mary went shopping for a new coat She found a red one she really liked
When she got it home, she discovered that it went perfectly with her favorite dress”
Represent this information by predicate logic sentences in such a way that you can solve questions below:
Q1 What did Mary go shopping for?
Q2 What did Mary find that she liked and what was its color?
Q3 Did Mary buy anything?
SinhVienZone.com https://fb.com/sinhvienzonevn
SinhVienZone.Com