Using Grammar Rules to Analyse English Sentences

Abstract

This chapter describes the use of the special syntax provided in Prolog for analyzing grammar rules: the operator -->/2, the predicate phrase/2 and braces to enclose ’regular’ Prolog used in conjunction with grammar rules. A simple grammar able to deal with basic sentences is defined. Predicates are given to enable the validity of sentences presented as lists of words to be established and to extract important information such as the type of each noun_phrase from valid sentences. Finally, predicates are defined to convert sentences in standard English into the ’list of words’ form required by the grammar rules.

After reading this chapter you should be able to:

• Understand and use the special syntax provided in Prolog for analyzing grammar rules.

• Define a simple grammar able to deal with basic sentences of English.

• Define predicates to enable the validity of sentences presented as lists of words to be established and to extract important information such as the type of each noun phrase from valid sentences.

• Define predicates to convert sentences in standard English into the ’list of words’ form required by Prolog grammar rules

Practical Exercise 12

Extend the grammar rules given at the end of Section 12.2 to allow for the possibility of an adverb at the end of a sentence of type s3 or s4. Define the following words as adverbs: well, badly, quickly, slowly.