1. Fill in the blanks with True or False. Justify your answers by showing how you evaluate each sentence. [10 points] A. If A is False and B is True, then "A |= B" is .................... B. (a: (a=a) negative(a) ) (a: a=a) is ......................

2. If X and Y are two propositional symbols, then {x=.........., Y=.........} would be a model in which the knowledge base (i.e., X Y X Y) is true. Justify your answer by showing how the model possibly produces a True value for the knowledge base (aka KB).

3. A knowledge base consists of W, X, Y, and Z as propositions. How many models (i.e., those which result in a true value) are there for the following sentence in the knowledge base? [10 points] W X Y Z

1. Fill in the blanks with True or False. Justify your answers by showing how you evaluate each sentence. [10 points] A. If A is False and B is True, then "A =B " is B. (a:(a=a) negative (a))(a:a=a) is 2. If X and Y are two propositional symbols, then {x=..,Y=..}would be a model in which the knowledge base (i.e., XYXY ) is true. Justify your answer by showing how the model possibly produces a "True" value for the knowledge base (aka KB). [10 points] 3. A knowledge base consists of W,X,Y, and Z as propositions. How many models (i.e., those which result in a true value) are there for the following sentence in the knowledge base? [10 points] WXYZ