2.0 Introduction

2.1 Grammars

2.2 Ambiguity

2.3 Summary

Web References

Exercises

A sentential form is any string derivable from the start symbol. Thus, in the derivation of a + a * a , E + T * F and E + F * a and F + a * a are all sentential forms as are E and a + a * a themselves.

A sentence is a sentential form consisting only of terminals such as a + a * a. A sentence can be derived using the following algorithm:

        Algorithm 
          Derive String 
        
        String := Start Symbol
        REPEAT
          Choose any nonterminal in String.
          Find a production with this nonterminal on the left-hand side.
          Replace the nonterminal with one of the options on the right-hand
            side of the production.
        UNTIL String contains only terminals.