Chapter 3: Decision Making Flashcards
What is a knowledge base made out of?
Sentences
What is the syntax of sentences?
Propositional/Predicate logic
What is meaning of sentences?
Semantics
What does M(s) denote
All models where the sentence s is true.
What does a entails b mean?
This means that if a is true then b is true. In model terms M(b) is a subset of M(a).
What is inference?
Inference is the reasoning process of deriving logical consequences of premise
What is an inference algorithm that derives entailed sentances?
Sound or truth preserving
Why is soundness highest priority?
An unsound inference would make up stuff as it goes to reach it’s conclusion (useless)
When is an inference algorithm complete?
If it can derive any sentence that is entailed
When is a sentence valid?
If it is true in all models
When is a sentence satisfiable?
If it is true in some models
What is a proof?
A chain of conclusions that lead to a desired goal
What is Monotonicity?
Set of entailed sentences can only increase if more information is added into knowledge base
Can Proof by Resolution always find an answer if it exists?
True
What is Proof by contradicition?
A proof by resolution technique, which adds the opposite of what we are trying to prove into the KB and tries to obtain an empty clause (contradiction).