Use Prolog to get data model paths from language rules? - prolog

Question

I want to build a semi-natural language interface for a data warehouse. A simple data model looks for example like this:
Company
- attribute 'name'
- reference to 'Departments'
Department
- attribute 'type'
- reference to 'Employees'
Employee
- attribute 'age'
- attribute 'salary'
And I would like to make queries like so:
ACME employees, Bugs Bunny salary, ACME department types etc.
For input that is not in the grammar, I would call the database and resolve say ACME into Company.
... and turn the queries into paths that my database language will understand:
[Company].departments.employees, [Employee].salary, [Company].departments.type.
I remember using SWI-Prolog way back when to parse English sentences and say if they are correct. Is Prolog still the way to go in this case?
Thanks

Answer 1

Even, better, I now use DCG with embedded Prolog rules.
So, for a model that has classes and attributes like this:
c(company, class(company)) --> [company].
a(company, attribute(name)) --> [name].
I can ask for attributes of a class of a class:
q(q(A,C1,C2)) --> a(T1,A), [of], c(T1,C1)
,[of], c(T2,C2), {is_child(T1, T2)}.
And get a tree back as an answer.

Answer 2

In SWI-Prolog, there is Chat80 ready to install. I think could be very similar to what you are after, mutatis mutandis.
Just a sample query from the session log (note: was my own old port of chat80 to SWI-Prolog, the pack is presumably more functional, but I haven't tried to run):
what rivers are there ?
Parse: 0.0168457sec.
whq
$VAR
1
s
np
3+plu
np_head
int_det(B)
[]
river
[]
verb(be,active,pres+fin,[],pos)
void
[]
Semantics: 0.0170898sec.
answer([B]) :-
river(B)
& exists B
true
Planning: 0.0sec.
answer([B]) :-
river(B)
& exists B
true
amazon, amu_darya, amur, brahmaputra, colorado, congo_river, cubango, danube, don, elbe, euphrates, ganges, hwang_ho, indus, irrawaddy, lena, limpopo, mackenzie, mekong, mississippi, murray, niger_river, nile, ob, oder, orange, orinoco, parana, rhine, rhone, rio_grande, salween, senegal_river, tagus, vistula, volga, volta, yangtze, yenisei, yukon and zambesi.
Reply: 0.166992sec.
The logical form required by discourse to answer a query it's the central point of the system. Not really easy to craft from ground!
I read the book Prolog and Natural Language Analysis, F.Pereira, S.Shieber, 1987
(translated in Italian), still my preferred! The english original it's freely available here.

Answer 3

Have ended up with this example that translates a 'sentence' into a path in the model:
% root classes
class(ceo).
% model relations
attribute_of(age, ceo).
attribute_of(salary, ceo).
% grammar of relations
attribute('age', age).
attribute('salary', salary).
attribute('money', salary).
% answer format
answer([Class, Attribute], Class, Attribute).
% language rules
% query(Attribute,'of',Object, Answer).
query(AttributeQ, 'of', ClassQ, Answer) :-
db(ClassQ, Class), attribute(AttributeQ, Attribute), attribute_of(Attribute, Class), answer(Answer, Class, Attribute).
% database
db('Bugs Bunny', ceo).
As an example, the following query:
?- query('age','of','Bugs Bunny', Answer).
...gives me:
Answer = [ceo, age].