1. Prolog programming Introduction to Prolog
CS370d

2. What is Prolog programming?
Prolog is a programming language for symbolic , non-numeric commutation.
It solves problems that involve objects and relations between objects.

3. Defining relations by facts
The fact that Tom is a parent of Bob can be written in prolog as:
parent(tom, bob).
tom and bob are objects,
parent(tom, bob) is a relation between these objects.

4. Defining relations by facts
The whole family tree can be described by the following facts:
pam
tom
bob
liz
ann
pat
jim

5. Defining relations by facts
The whole family tree can be described by the following facts:
parent(pam,bob).
parent(tom,bob).
parent(tom,liz).
parent(bob,ann).
parent(bob,pat).
parent(pat,jim).
pam
tom
bob
liz
ann
pat
jim

6. Defining relations by facts
We can also add information about the gender of the people by the following facts:
female(pam).
male(tom).
male(bob).
female(liz).
female(pat).
female(ann).
male(jim).

7. Defining relations by facts
female(pam) is a Unary relation
parent(bob,pat) is a Binary relation.
Think about this relation:
sex(pam, feminist).

8. SWI-Prolog
SWI-Prolog editor is an open source implementation of the programming language . Prolog is a free software and you can download it from here:

9. SWI-Prolog Getting started:
Any Prolog program in SWI-Prolog is written in a file with extension .pl. You can write your own one by following these steps:

10. SWI-Prolog After opening SWI Prolog environment, choose
file -> new to create a new.pl file.

11. SWI-Prolog
This will open a new window to create the new file, choose any name for your programs (here we name it tree) then choose to save it.

12. SWI-Prolog
Now the .pl file we have just created will be opened, and we can write our own program. Let's write the following facts about parent , male and female relationships:
parent(pam,bob). parent(tom,bob). parent(tom,liz). parent(bob,ann). parent(bob,pat). parent(pat,jim). female(pam). female(liz). female(pat). female(ann). male(tom). male(bob). male(jim).

13. SWI-Prolog

14. SWI-Prolog
Compile your program. Compile - > Make

15. SWI-Prolog
Then click “ OK ” to save the changes on your file.

16. SWI-Prolog
In SWI Prolog environment, load your program by file -> consult. Then choose your program .

17. Questions in prolog. Prolog can posed questions about any relation.
So, we can ask a question about Parent relation,
For example : Is bob a parent of Pat?
?- parent(bob,pat).
The answer will be true.

18. Exercise 1:
Write prolog program of your own family tree .