Given sentences (A E) below,

A. All great chefs are French.

B. All Frenches enjoy good food.

C. Paul or Sophie is a great chef.

D. Paul is not a great chef.

E. Query: Who enjoys a good food?

1) write them in their 1st -order logical representations using the following predicates and constants: Predicates: GC great chef(s), F French, EF enjoy good food, Constants: Paul, Sophie

2) Answer the query by forward chaining method. Draw the proof trees showing the substitutions step by step. Refer to the slide #23 - #25.

3) Convert the sentences in 1) to the definite clauses in CNF, suitable for Knowledge_Base through Skolemization, etc. if necessary. Refer to the slide #42.

4) By applying resolution, answer the query. Show the steps of proof by drawing the resolution tree. Refer to the figure in slide #43 of Chap. 9.