In this chapter 5, it introduces higher-level techniques for implementing search algorithms such as:
recursive search implements depth-first search with backtracking in a more concise,natural fashion than in chapter 3 and form the basis for many of the algorithms; recursive search is augmented through the use of unification to search the state space generated by predicate calculus assertions
pattern-directed search algorithm is the basis of PROLOG and many of the expert system shells discussed in chapter 7
production systems is a general architecture for pattern-defined problem solving that has been used extensively both to model human solving and to build expert systems and other AI applications
blackboard representation is for another AI problem-solving