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posted Oct 15, 2013, 9:45 PM by Neil Mathew   [ updated Oct 16, 2013, 3:17 AM ]

WAP - More Mathematical Functions.

posted Aug 6, 2013, 12:37 AM by Neil Mathew




Maths.pl

natural_number(N) :- integer(N),N>0.

add(M,N,Sum) :- Sum is M+N.
sub(M,N,Diff) :- Diff is M-N.
mul(M,N,Prod) :- Prod is M^N.
div(M,N,Sol,Rem) :- Sol is M/N, Rem is mod(M,N).
exp(M,N,Exp) :- Exp is M**N.

factorial(0,1).
factorial(N,F) :- N>0, M is N-1, factorial(M,Fm), F is N*Fm.
Queries:


11 ?- factorial(3,F).
F = 6 .

12 ?- 
|    .
ERROR: Stream user_input:5:57 Syntax error: Unexpected end of clause
12 ?- natural_number(5).
true.

13 ?- natural_number(-1).
false.

14 ?- factorial(5).
ERROR: Undefined procedure: factorial/1
ERROR:     However, there are definitions for:
ERROR:         factorial/2
false.

15 ?- factorial(5,F).
F = 120 .

16 ?- div(7,3,Sol,Rem).
Sol = 2.3333333333333335,
Rem = 1.
Now, LCM, GCD:


gcd(A,B,GCD):- A=B,GCD=A.
gcd(A,B,GCD):- A<B,NB is B-A, gcd(A,NB,GCD).
gcd(A,B,GCD):- A>B, NA is A-B,gcd(NA,B,GCD).

lcm(X,Y,LCM):-gcd(X,Y,GCD), LCM is X*Y//GCD. 

Lab work:

1. arith
2. facotorial
3. gcd/lcm
4. rerlation (family)
5. health

0 Intro

posted Aug 5, 2013, 11:40 PM by Neil Mathew   [ updated Aug 6, 2013, 12:01 AM ]

To transform an English sentence to Predicate Logic, we remove unnecessary terms.
This leaves only the relationship and the entities involved, known as arguments.

Predicate Logic
Ex:  A pie is good   =   good(pie)
The relation is ‘good’, the relation’s argument is ‘pie’.

Prolog Rules
To infer facts from other facts, Prolog uses Rules. 
Ex:  Bill likes cars if they are red =          
      likes(bill, cars):- red(cars).

By the way, in prolog, ‘:-’ is pronounced ‘if’.

Prolog Queries
 We may want to ask, “What does ali like?”
In Prolog syntax, we ask:  
likes(ali,What).  
Note: capital W on what

Examples:
a_kind_of(aa,ship).
a_kind_of(bb,ship).

part_of(aa,jordanian_navy).
part_of(bb,jordanian_navy).

part_of(jordanian_navy,jordanian_government). a_kind_of(jordanian_government,government).

color(ship,red). a_kind_of(aa,ship). 

a_kind_of(bb,ship).

part_of(aa,jordanian_navy).
part_of(bb,jordanian_navy).
part_of(jordanian_navy,jordanian_government). 

a_kind_of(jordanian_government,government).
color(ship,red).



Parts of a Prolog Program

All programs written in Prolog contain at least 4 parts:
  • DOMAINS 
  • PREDICATES 
  • CLAUSES 
  • GOALS 

Domains:

The section of code where we define the legal values for any type that is not defined as a standard type.  

Predicates:

The predicate section is where we define predicates to be used in the CLAUSES section and define the domains for their arguments. 

Symbolic name of a relation
We found it best to think of predicate declarations as function prototypes
Ex:  age(string, integer)

Clauses:
Clauses are the heart of the program.
A clause is an instance of a predicate, followed by a period.
Clauses are of two types:
  • Facts
  • Rules

>> Facts:
Facts in the CLAUSE section are relations that are known to be true by the programmer. A property of an object or a relation between objects. 
Ex: red(car)

>> Rules:
Used to infer other facts. Property or relation known given the fact that some other set of relations are known.

Ex: Jane can eat food if it is a vegetable on the doctor’s list.
Can_eat(jane, X):- food(X), vegetable(X), doc_list(X).

Goals:
Part of program where queries are made.
Can be singular or compound.

Each part of a compound goal is known as a subgoal. 
To satisfy a compound goal (or query) each subgoal must itself be satisfied by the system

Ex:  What are the things do Bill and Cindy both like (in common)?
In Prolog:
likes(bill, What), likes(cindy, What).


Attached a ppt with more information on the AI page.

WAP to perform simple arithmetic operations.

posted Jul 30, 2013, 12:11 AM by Neil Mathew


COMMANDS ON SWI-Prolog Shell









    //  Note the variables should not be in small case. It needs to have at least one Upper Case character.

1 ?- a is 2.
false.

2 ?- A is 2.
A = 2.

3 ?- number is 2.
false.

4 ?- Number is 2.
Number = 2.
    //  Note:  Commands like 'is' is case sensitive.


1 ?- A IS 7.
ERROR: Syntax error: Operator expected
ERROR: A 
ERROR: ** here **
ERROR: IS 7 . 
1 ?- A is 7.
A = 7.
// Note:  Separate the statements using commas. End the line with a dot.


1 ?- X is 7. Y is 3. Z is X+Y.

X = 7.


Y = 3.

ERROR: is/2: Arguments are not sufficiently instantiated
4 ?- X is 7, Y is 3, Z is X+Y.
X = 7,
Y = 3,
Z = 10.
// NOte the difference between = and is


1 ?- X is 7, Y = 10, C is X + Y.
X = 7,
Y = 10,
C = 17.

2 ?- X is 7, Y = 10, C = X + Y.
X = 7,
Y = 10,
C = 7+10.


Lisp and Prolog 1

posted Jul 29, 2013, 11:36 PM by Neil Mathew   [ updated Jul 29, 2013, 11:58 PM ]

   

female(mary).


father(X,Y):- male(X), parent(X,Y).



SAMPLE PROLOG FILE: familytree.pl

parent(pet,mike).
parent(pet,july).
parent(pet,amenda).
parent(mary,mike).
parent(mary,july).
parent(mary,amenda).

female(mary).
female(july).
female(amenda).
male(mike).
male(pet).

sibling(mike,july).
sibling(mike,amenda).
sibling(amenda,mike).
sibling(july,mike).
sibling(july,amenda).
sibling(amenda,july).

father(X,Y):-male(X),parent(X,Y).
mother(X,Y):-female(X),parent(X,Y).
brother(X,Y):-male(X),sibling(X,Y),X\=Y.
sister(X,Y):-female(X),sibling(X,Y),X\=Y.
SAMPLE QUERIES:




1-5 of 5

ć
Neil Mathew,
Aug 5, 2013, 11:46 PM