AI Spring 2010 Lecture 10

AI Spring 2010 Lecture 10 - Artificial Intelligence Lecture...

Info icon This preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Click to edit Master subtitle style Artificial Intelligence Lecture 10: First Order Logic (FOL) (Part III: Knowledge & Reasoning, Chapter 8) Spring 2010 Instructor: Paul S. Rosenbloom
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Midterm 1 £ Here, Tuesday, February 16, 12:30-1:50 l Open book and notes but no electronic devices of any sort l Must be your own work l Covers chapters 1-8 except 6 and 4.2 (3rd Ed.) l Course is based on 3rd Ed., but I am not aware of anything on exam that depends on the differences £ Review session today 2-2:50, ZHS 159 22
Image of page 2
33 Today’s Lecture £ Why FOL? £ Syntax and semantics of FOL £ Using FOL £ Wumpus world in FOL £ Knowledge engineering in FOL
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
44 Pros and Cons of Propositional Logic r It allows partial/disjunctive/negated information l Unlike most data structures and databases J It is compositional o meaning of B1,1 P1,2 derived from meaning of B1,1 and P1,2 o Meaning of sentences is context independent o Unlike natural language and computer programs, where the meaning of a sentence depends on context or usage l It has very limited expressive power l Unlike natural language l E.g., cannot say "pits cause breezes in adjacent squares“ l Except by writing one sentence for each square
Image of page 4
55 Assumptions about the World £ Propositional logic assumes the world consists of a set of “black box” facts, which it represents via symbols and combines via connectives £ First-order logic, more like natural language, provides more structured way of representing world l Objects : Things you can talk about l E.g., people, houses, numbers, colors, baseball games, wars l Relations : Relations among objects that can be true or false l E.g., red, round, prime, brother of, bigger than, part of, comes between l Functions : Functions of objects that return unique values l E.g., father of, best friend of, one more than, plus, … l Can be viewed as relation where one argument has at most one value E.g., Father-of(Fred, George) ° Father-of(Fred) = George l FOL represents each of these, plus uses connectives, and more
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
66 Example Domain Arithmetic on Natural Numbers £ Objects l Non-negative numbers (0, 1, …) £ Relations l NatNum, =, <, >, … £ Functions l Successor, +, -, x, integer division, remainder, exponentiation,… E.g., >(+(5, 20211), -(5111,777)) ° =(5,+(3,2))
Image of page 6
Example Domain English History £ Objects l Richard, John, crown, left legs £ Unary Predicates l Crown, King l King(John) £ Binary Predicates l Brother, OnHead l OnHead(crown, J) £ Functions l LeftLeg(R) = LL1 77
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
88 Representational Commitments in Logic £ Ontological Commitment: What kinds of things exist in the world l Propositional: facts that hold or do not hold l First-Order: objects with relations among them that hold or do not hold £ Epistemological Commitment: Form/level of belief * * * Likelihood of truth versus degree of truth
Image of page 8
99 Syntax of FOL Basic Elements £ Constants KingJohn, 2, Crown,...
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern