Symbolic Logic was being used to represent knowledge even before the advent of digital computers. Today First Order Predicate Logic (FOPL) or simple Predicate Logic plays an important role in AI for the representation of knowledge. A familiarity with FOPL is important. It offers the only formal approach to r4easoning that has a sound theoretical foundation, this is important in the attempts to automate the reasoning process, because inference should be correct and logically sound. The structure of FOPL is flexible and it permits accurate representation of natural language reasonably well.
Logic is a formal method for reasoning. Many concepts which can be verbalized can be translated into symbolic representations which closely approximate the meaning of these concepts. These symbolic structures can then be manipulated in programs to deduce various facts, to carry out a form of automated reasoning . in predicate logic statements from a natural language like English are
translated into symbolic structures comprised of predicates, functions, variables, constants, quantifiers and logical connectives. The symbols form the basic building
blocks for the knowledge, and their combination into valid structures is accomplished using the syntax of FOPL. Once structures have been created to represent basic facts, inference rules may then be applied to compare, combine and transform these “assumed” structures into new “deduced” structures. This is how automated reasoning or inferencing is performed.