How AI Works

Bird.pro as an example

An Expert System enabled by Prolog

An inferencing system enabled by Prolog, or other AI language like Lisp

Information is all stored as attribute-value pairs.

The attribute is represented as a predicate, and the value as the argument to the predicate.

For example, the attribute-value pair "color-brown" is stored "color(brown)".

What is Prolog?

Programming in LogicFrom a foundation of logical theorem

proving, originally used for research in natural language processing

Declarative programming rather than Procedural programming versus

Procedural Programming

Specify what procedures to take Follow the specified procedures to work out the

answer E.g. To find out the average of a set of numbers,

we need to: Sum up all the numbers Count the total number of entries Divide the sum by the total number Report the answer

Corresponding to procedural knowledge

Declarative Programming

A collection of small modular units, called predicates

Can be added and tested separatelyCorresponding to declarative knowledge

Simple programme

Database:person(peter).

person(jane).

person(nancy).

Query: Enter:person(peter). Reply: yes.

Query: Enter: person(X). Reply: X=peter; X=jane; X=nancy

A little more

Add:likes(peter,dog)likes(jan,cat)likes(nancy,snake)animal(dog).animal(cat).animal(snake)pet(X,Y):-person(X),animal(Y),likes(X,Y).

Test:pet(peter,dog).pet(nancy,X).pet(X,cat).

How “bird.pro” Works

main :- identify.

identify:- retractall(known(_,_,_)), % clear stored information bird(X), write('The bird is a '),write(X),nl.identify:- write('I can''t identify that bird'),nl.

To start the process, type “main.”, the system tries to verify identity

To find out what bird it is

Write the answer if found

If not found

bird(laysan_albatross):- family(albatross), color(white).bird(black_footed_albatross):- family(albatross), color(dark).bird(fulmar):- order(tubenose), size(medium), flight(flap_glide).bird(whistling_swan):- family(swan), voice(muffled_musical_whistle).bird(trumpeter_swan):- family(swan), voice(loud_trumpeting).

If the bird belongs to the albatross family and its color is white,Then the bird is laysan albatross