1. PROLOG “Programmation en Logique”
Juan Chen Cory Taylor Lucas Lopes Justin Khan

2. Topics covered Compilers History of the Language
Features of the language
Modifications and sub-branches
Modern use of language

3. History Created by Alain Colmerauer and Philippe Roussel in 1972
Groupe d'Intelligence Artificielle
University of Marseille
With collaboration from Robert Kowalski of University of Edinburgh
Researching automatic proving of theorems
Then branched out into other dialects
Main branches stayed in their respective universities

4. Other Offshoots of Prolog
CLP(R)
CHIP
Prolog III
Trilogy
HCLP
FCP
Strand

5. More on Prolog Declarative Logic Language
Among the first logic programming languages
Original purpose: Natural Language Processing
Current Use: (predominately) A.I. Programming
Still very popular
Prolog standardization created in 1995
Individual parts of the language defined to ensure the language core is fixed.

6. WARREN ABSTRACT MACHINE (WAM)
Developed in 1983
Ushered the “Wonder years” of prolog implementation
A structure-copying execution model for PROLOG
Standard implementation technique
High level instruction set
Extremely memory efficient

7. Vienna Abstract Machine (VAM)
Considerably faster than WAM
VAM does argument setup and Argument Unification Simultaneously
These are then combined into a single operation, saving work-time.

8. List of PROLOG compilers
BinProlog
SWI Prolog (what we will be using later)
GNU Prolog
Kernel Prolog
Open Prolog
Allegro Prolog
ECLiPSe Prolog
And several others

9. Modern Use A.I. Programming Database Design and Implementation
NASA's “clarissa” in the ISS
Database Design and Implementation
MOVIS software – companies like Ericsson use the graphical prolog tool for rule-based systems and business solutions
Computer Science Teaching Tool
Used in colleges for instruction in A.I.
Expert Systems (Human Level Decision Making)
Expert Systems tutorials in prolog include an E.S. that solves a rubik's cube.

10. Syntax Program logic is expressed in terms of relations
Computations are queries over these relations
Single data type: TERM
Relations defined by clauses

11. The TERM Terms are divided amongst many different sub-types Atom
Numbers
Variables
Compound Term

12. Compound Terms
Compound terms can be further divided into a few special cases
Lists
Strings

13. Features Supports recursion Relational Databases
Natural Language processing
Query Database Commands
Unification

14. Features Prolog automatically searches for an answer
Quantification Logic
a variable can have attributes---in other words, it is not just "If A and B then C" it can also be "If A(a,b,c) and B(m,n) then C(a,b,n)" where a, b, c, m and n are attributes of A, B and C. For example: If Between(x,y,z) and Between(x,k,y) then Between(x,k,z)" would be hard to express in any other language---it would certainly take more than one line in any other language

15. RULES AND FACTS
PROLOG programs describe relations, defined by means of clauses.
Rules are of the form: “Life:-Heartbeat.”
That is read as: “Life is true if Heartbeat is true”
Facts are of the form: “cat(Nyan).”
Which is equivalent to the rule: “cat(Nyan):- true.”

16. How to program prolog Program
Contain the facts and rules that will be used by the user of the program. It contains all the relations that makes a program.
Query
When you launch a program you are in query mode. This mode is represented by the sign ? -  at the beginning of the line. In query mode you ask questions about relations described in the program.

17. Facts Facts Facts with arguments ?-factname.
In Prolog we can make some statements by using facts. Facts either consist of a particular item or a relation between items.
?-factname.
We can ask a query of Prolog by asking like this.
Facts with arguments
relation(<argument1>,<argument2>,....,<argumentN> ).
More complicated facts consist of a relation and the items that this refers to. These items are called arguments. Facts can have arbitrary number of arguments from zero upwards. A general model is shown below:

18. Variables How do we ask eats(cory, apples). ?-eats(cory, what).
Wrong, “what” is not an legal variable
What are legal variables? Capitial letters at the start
?-eats(cory,What).
What = apples.
?-eats(Who,apples).
Who = cory.
Now say we have the following in our database of facts
eats(cory,banana).
If we ask ?- eats(cory,What). We get
What = banana

19. Unification Consider we have a library.
book(1,hitchhikersguide,adams).
book(2,themeaningofliff,adams).
book(3,title3,author2).
book(4,title4,author3).
Query you could ask
?- book(_,_,adams).
It would respond with a TRUE output, saying that that is indeed an author.
If we wanted to know which book adams wrote. We would ask it like this.
?- book(_,X,adams).
This would give us a response of below.
X=hitchhikersguide ;
X=themeaningofliff ;

20. Rules
Consider the following sentence : 'All men are mortal' We can express this thing in Prolog by :
mortal(X) :- human(X).
The clause can be read as 'X is mortal if X is human'.
To continue with this example, let us define the fact that Socrate is a human. Our program will be
human(socrate).
Now if we ask to prolog :
?- mortal(socrate).
Prolog will respond :
Yes
In order to solve the query -? mortal(socrates). Prolog uses the rule we gave it. In order to prove that someone is mortal we can prove that he is human. So from the goal mortal(socrate) Prolog generate the subgoal human(socrate).

21. Adding Rules
You can also add rules or facts with the instruction for example. Assert(fact1) which will add the fact called fact1.
The predicates added with this command are considereted like any other in the source of the program.
assert(c). Add the rule c in the database.assert()
retract(c). Remove the c from the database.retract(c)
asserta(c). Add c at the beginning of the database.asserta()
assertz(c). Add c at the end of the database.assertz()

22. Compiler
The compiler we used for this demonstration was called SWI- Prolog
It was created by Jan Wielemaker from the University of Amsterdam, department of Social Science Informatics .
It was written in ASCI-C and should configure nicely with most Unix machines that have an ASCI-C compiler.
Ports where made for Linux, Windows, MacOSX.
It is open source “free”.
Information should be free yo.

23. Sample programs
Hello World
Recursion
Books
Query Exploration.
Lists

24. Operators =,is,<,>,=<,>=,==,=:=,/,*,+,-,mod,div
Binary trees
y*5+10*x are written in Prolog : +(*(y,5),*(10,x)).
Prolog uses “is”
X is
Prolog responds
X = 7
yes

25. Bibliography www.stackoverflow.com www.learnprolognow.org
ory.htm
is400/prolog/prolog.html