The logical AND therefore is used to narrow the scope of the result, requiring the co-occurrence of terms, and will in general decrease the number of hits. The symbol used to indicate the logical AND operation is the asterisk (*). Thus, for example, to retrieve documents about food with the term "Africa" in the title and written by Smith one could use the logical AND operators as follows:
TI=Africa * A=Smith * D=food$
Note that as for the logical OR, the order
in which the terms are given is irrelevant.