Answer Happy

only (1) D. (i), (ii) and (iii) whereas backward chaining systems are 20. Forward chaining systems are A. Data driven, Data driven B. Goal driven, Data driven C. Data driven, Goal driven D. Goal driven, Goal driven 21. A horn clause is A. A clause in which no variables occur in the expression B. A clause that has at least one negative literal C. A disjunction of a number of literals D. A clause that has at most one positive literal 22. Reasoning strategies used in expert systems include: A. Forward chaining, backward chaining and problem reduction B. Forward chaining, backward chaining and boundary mutation C. Forward chaining, backward chaining and back propagation D. Backward chaining, problem reduction and boundary mutation