

                           G E O B A S E
                           *************


Geobase is a natural language interface to U.S. geography containing
the following information:

Information about states:
  Area of the state                        In square miles
  Population of the state                  In citizens
  Capital of the state
  Which states border a given state
  Rivers in the state
  Cities in the state
  Highest and lowest point in the state    In feet

Information about rivers:
  Length of river                          In miles

Information about cities:
  Population of the city                   In citizens


You can retrieve any or all of this information by asking questions
in normal English. Some sample queries:

  - states

  - give me the cities in california.

  - what is the biggest city in california ?

  - what is the longest river in the us?

  - which rivers are more than 1 thousand miles long?

  - what is the name of the state with the lowest point ?

  - which states border alabama ?

  - which rivers do not run through texas

  - which rivers run through states that border the state
    whose capital is austin?


You can modify Geobase as you work with it. If
it doesn't understand a word in one of your questions, you can
add the word to the language definition. The language is defined in a
number of relations, the most important one being the schema. A
schema is a description of the logical structure of a database.
In Geobase, the schema is the "entity network" for the
language.A schema entry follows the form: ENTITY ASSOCIATION
ENTITY; this signifies that the two entities are bound together
by the given association.

To display the relations and their schema, select View Language from the main
Geobase menu, then choose one of the items listed below.


1. Schema of relations

   The geography data are stored in a number of relations. The
   schema for these relations is listed here.

2. Schema of questions

   The schema for all possible questions that can be asked is listed
   here. For example, one possibility is:

   > population  of  city <

   That is, what is the population of a given city?

3. Names of entities

   All known entities are listed her.

4. Synonyms for entities

   Synonyms for entities are allowed. The previously defined synonyms
   are listed here; you can also add synonyms to the database
   dynamically.

5. Synonyms for associations

   Synonyms for associations are allowed, and can consist of more than one word.

6. Words that are ignored

   Some words are simply ignored by the system, since they are not
   directly relevant to the meaning of questions. Ignored words are
   listed here.

7. Units for entities

   The units of measure for different entities are listed here. For
   instance, the unit for population is "number of citizens".

8. Synonyms for relational operators

   There are several ways to say that a city is "bigger than" 1 million
   citizens or that a river is "shorter than" 1 thousand miles. These synonyms
   are listed here.

9. Alternative ways to designate the minimum

    The different ways to designate adjectives for "minimum" are listed here.

10. Alternative ways to designate the maximun

    The different ways to designate adjectives for "maximum" are listed here.
