# Shared Flashcard Set

## Details

AI Exam 3
Notes to Prep for Dr. Mooney's 4th exam in AI
20
Computer Science
12/04/2012

Term
 General convert KB to Conjunctive Normal Form (CNF)
Definition
 - Functions are eliminated - All quantifiers are eliminated - Result is in clausal form
Term
 KB to CNF Algorithm
Definition
 1. Eliminate implication 2. Reduce scope of not to single terms 3. Standardize variables 4. Eliminate existential quantifiers 5. Move quantifiers to left (prenix normal form) 6. Drop prefix 7. Convert into conjunctions of disjuncts 8. Write as a set of separate clauses, one per conjunct 9. Rename variables so each clause has unique variables
Term
 Basic components of First Order Logic (FOL)
Definition
 1. Objects 2. Relations among objects 3. Functions
Term
 FOL Model
Definition
 - Represents a possible world - A model contains a set of objects
Term
 Total Functions
Definition
 - Functions in FOL are all total functions - Total functions return an object for all sets of arguments
Term
 Term
Definition
 An expression that refers to domain elements (constant symbols, variable symbols, or function expressions).   A "ground term" has no variables in it
Term
 Sentences
Definition
 AKA Well Formed Formuli (wff), sentences represent truth values.
Term
 DeMorgan's Law for Quantifiers: [image]
Definition
 [image]
Term
 DeMorgan's Law for Quantifiers: [image]
Definition
 [image]
Term
 DeMorgan's Law for Quantifiers: [image]
Definition
 [image]
Term
 DeMorgan's Law for Quantifiers: [image]
Definition
 [image]
Term
 Database Semantics
Definition
 - An alternative semantics intended to simplify representation -Includes the following:    - Unique names assumptions    - Closed world assumption - Atomic sentences whose truth values are not known are assumed to be false    - Domain closure - The only objects in the domain are those named by constants
Term
 Axiom
Definition
 A basic fact, that MAY represent a definition. Simple facts, however, are often expressed by atomic sentences, which are NOT definitions.
Term
 Definition
Definition
 Specifies equivalence between two facts using a biconditional or logical equivalence. Definitions are a subset of axioms
Term
 Theorem
Definition
 Anything inferred from the KB. Adding theorems does not add new information, but they decrease the amount of inference required to perform later inferencing.
Term
 Independent Axiom
Definition
 An axiom that cannot be derived from others
Term
 TELL(KB, sentence)
Definition
 Used to add knowledge to the KB.  These statements are called assertions.
Term