AI Class Notes (Highlights) on November 12th 2008:-

(Page numbers in reference with the AI text book)

• Pg 253 -> Substitution
  • Example: Pit(x)=[1,2] position of x
  • Re-use variables
  • Ground term (constant values for substitution)
• Pg 273 -> Existential Instantiation (Greedy->John->Evil....)
  • Example: "k" is like searching in yahoo
  • where "theta"={x/John} where John represents ground term
  • Existential quantifier means it exists only once, so therefore its applied once because we don't know whether we have more than one (i.e why its used one time)
  • On the other hand, Universal quantifier can be used several times since its "for every"
• Pg 276 -> Marry Unification & Substitution
  • Approach 1: x is John, y is John => x=y -> Inference rule -> unification -> first order normal form
  • Approach 2: Pg 277, Renaming variables for avoiding syntactic errors (Its not trivial differences but its significant differences)
• Pg 295 -> Conjunctive Normal Form (9.5 Resolution)
  • If there exists Pit(x) then we can assume for all Pit(x)
  • Pay attention to sequence (precedence) and then standardize in order to avoid errors.
  • Skolemization (asking user name)
  • Refer Pg 296 for all steps involved.
• Python -> Propositional
  • Walk through this resolution with some wumpus stuff
• Prep @ *"PrepLab3AI"*

-- KavithaAshwin - 13 Nov 2008