1. Proposition symbols F = Dardar can fly B = Dardar is a bird P = Dardar is a plane S = Dardar is Superman

2. Sample knowledge base (KB)  Suppose we know the following: Dardar can fly implies that he is either a bird, a plane or Superman Dardar can fly  KB consists of the following sentences F  B  P  S F  Suppose we are told that Dardar is not a bird and that he is not a plane  Add the following sentences to the knowledge base B P

3. Knowledge base as a conjunction of sentences  What we know: F  B  P  S F B P  Equivalently: KB = (F  B  P  S)  F  B  P  Question: Can we conclude that Dardar is Superman?

4. Inference by enumeration  Get all true-false possibilities for F, B, P, S then check each possibility against KB:(F  B  P  S)  F  B  P FBPSKB ffff? ffft? fftf? fftt? ftff? … tttt?

5. Inference by enumeration FBPSKB tffff tfftt tftff tfttf ttfff ttftf tttff ttttf FBPS fffff ffftf fftff ffttf ftfff ftftf fttff ftttf

6. Inference by enumeration FBPSKB tffff tfftt tftff tfttf ttfff ttftf tttff ttttf FBPS fffff ffftf fftff ffttf ftfff ftftf fttff ftttf Dardar is Superman