Semantic Grammar
Semantic grammar lies between ELIZA and a more general English grammar. It uses a grammar in which nonterminal symbols have meaning in the domain of application.
<S> --> WHAT <CUST> ORDERED <PART>
<MODS>
<CUST> --> CUSTOMER | CUSTOMERS <LOC>
<LOC> --> IN <CITY>
<CITY> --> AUSTIN | SEATTLE | LA
<PART> --> WIDGETS | WIDGET BRACKETS
<MODS> --> IN <MONTH> | BEFORE <MONTH>
<MONTH> --> JANUARY | FEBRUARY | MARCH
WHAT CUSTOMERS IN AUSTIN ORDERED
WIDGET BRACKETS IN MARCH
Advantages: