Chapter 8

Arithmetic Program Examples

Chapter 8 2344-302 LP and Prolog

Factorial1.pro

predicates factorial(integer, integer)clauses

factorial(1, 1). factorial(N, Result) :-

N > 1,M = N-1, factorial(M, RET),

Result = N*RET. factorial(N,M) :-

M = N, write(“end of datatbase”).

Chapter 8 3344-302 LP and Prolog

Factorial2.pro

predicates factorial(integer, integer)clauses

factorial(1, 1) :- !. factorial(N, Result) :-

M = N-1, factorial(M, RET),

Result = N*RET.

Chapter 8 4344-302 LP and Prolog

Factorial Ex07EX03.pro

/* Recursive program to compute factorials. */

predicates factorial(integer, real)clauses

factorial(1, 1) :- !. factorial(X, FactX)

:- Y = X-1, factorial(Y, FactY),

FactX = X*FactY.

Chapter 8 5344-302 LP and Prolog

predicates factorial(integer, real) factorial_aux(integer, real, integer, real)/* Numbers likely to exceed 32767 are declared as reals. */clauses factorial(N, FactN) :- factorial_aux(N, FactN, 1, 1). factorial_aux(N, FactN, I, P) :- I <= N, !, NewP = P * I, NewI = I + 1, factorial_aux(N, FactN, NewI, NewP). factorial_aux(N, FactN, I, FactN) :- I > N.

Factorial Ex07EX07.pro

Chapter 8 6344-302 LP and Prolog

Factorial Ex07EX08.pro

/*Turbo Prolog 2.0 Chapter 7, Example Program 8*/predicates factorial(integer,real) factorial(integer, real, integer, real)

/* Numbers likely to exceed 32767 are declared as reals. */clauses factorial(N,FactN):- factorial(N,FactN,1,1). factorial(N, FactN, N, FactN):- !.

factorial(N, FactN, I, P):- NewI = I+1, NewP = P*NewI, factorial(N, FactN, NewI, NewP).

Chapter 8 7344-302 LP and Prolog

/* Ex3.6 from thai book */predicates status(symbol). sex(symbol,symbol). father(symbol,symbol). husband (symbol,symbol)clauses husband (suchart,malee). husband

(somchai,monta).

father(suchart,poo). father(somchai,tik). father(somchai,tum). father(somchai,ta). father(somchai,tu).

Status Ex3.6status.pro

sex(female,malee).

sex(female,monta).

sex(male,suchart).

sex(male,somchai).

sex(female,susy).

sex(male,mike).

Chapter 8 8344-302 LP and Prolog

status(X) :- sex(S,X),write(X, “ is “,S," "),nl,fail. status(X) :-

husband(X,W),!,write("married wife = ",W),nl,write(" Chiledren : "),nl,father(X,C),write(" ",C),nl,fail.

status(X) :- husband (H,X),!,write("married husband = ",H),nl,write(" Chiledren : "),nl,father(H,C),write(" ",C),nl,fail.

status(X) :- write(X, " is single. \n ").

Status Ex3.6status.pro

Chapter 8 9344-302 LP and Prolog

โจทย์�

จงเขี�ยนโปรแกรมภาษาโปรล็�อกเพื่��อคำ�านวณหาคำ�า

A = (X/B +B)/2

Chapter 8 10344-302 LP and Prolog

Ex5.2 Solution.pro

/* Ex5.2 from thai book *//* Find A = (X/B +B)/2 */

predicates solve(real,real,real).

clauses solve(A,X,B) :- A = (X/B + B)/2.

Chapter 8 11344-302 LP and Prolog

โจทย์�จงเขี�ยนโปรแกรมภาษาโปรล็�อกเพื่��อคำ�านวณหาคำ�า

AX^2 + BX + C = 0

X = ( -B +- sqrt(B*B -4AC))/2A

Chapter 8 12344-302 LP and Prolog

Ex5.3 Solution.pro/* Ex5.3 from thai book *//* Find AX^2 =BX + C = 0 *//* Find X = ( -B +-sqrt(B*B -4AC))/2A */

predicates solve(real,real,real). run(real,real,real). clauses run(A,B,C) :-

D = B*B - (4*A*C),solve(A,B,D),nl.

solve(_,_,D) :- D < 0, write("No solution"). solve(A,B,D) :- D = 0, X = -B / (2*A), write(" x = ",X),!. solve(A,B,D) :- S = sqrt(D), X1 = (-B + S)/(2*A), X2 = (-B - S)/(2*A), write(" x1 = ",X1," x2 = ",X2).

Chapter 8 13344-302 LP and Prolog

โจทย์�จงเขี�ยนโปรแกรมภาษาโปรล็�อกเพื่��อ

คำ�านวณหาคำ�าระยะห�างจากเม�อง 2 เม�องใดๆ

route(town, town, distance)

road(town1, town2, 200)

Chapter 8 14344-302 LP and Prolog

Ex18Ex02.pro : Distance/*Turbo Prolog 2.0 Chapter 18, Example Program 2 */

domains

town = symbol

distance = integer

predicates

road(town, town, distance)

route(town, town, distance)

clauses

road(tampa, houston, 200).

road(gordon, tampa, 300).

road(houston, gordon, 100).

road(houston, kansas_city, 120).

road(gordon, kansas_city, 130).

route(Town1, Town2, Distance) :-

road(Town1, Town2, Distance).

route(Town1, Town2, Distance) :-

road(Town1, X, Dist1),

route(X, Town2, Dist2),

Distance=Dist1+Dist2, !.

Chapter 8 15344-302 LP and Prolog

EX18EX01.pro : Animalpredicates animal_is(symbol) it_is(symbol) ask(symbol, symbol, symbol) positive(symbol, symbol) negative(symbol, symbol) clear_facts runclauses animal_is(cheetah) :- it_is(mammal), it_is(carnivore), positive(has, tawny_color), positive(has, dark_spots). animal_is(tiger) :- it_is(mammal), it_is(carnivore), positive(has, tawny_color), positive(has, black_stripes).

goal:

run

Chapter 8 16344-302 LP and Prolog

EX18EX01.pro : Animal (cont.)

animal_is(giraffe) :- it_is(ungulate), positive(has, long_neck), positive(has, long_legs), positive(has, dark_spots). animal_is(zebra) :- it_is(ungulate),

positive(has,black_stripes). animal_is(ostrich) :- it_is(bird),

negative(does, fly), positive(has, long_neck), positive(has, long_legs), positive(has, black_and_white_color). animal_is(penguin) :- it_is(bird), negative(does, fly), positive(does, swim), positive(has, black_and_white_color). animal_is(albatross) :- it_is(bird), positive(does, fly_well).

Chapter 8 17344-302 LP and Prolog

it_is(mammal) :- positive(has, hair). it_is(mammal) :- positive(does, give_milk).

it_is(bird) :- positive(has, feathers). it_is(bird) :- positive(does, fly),

positive(does,lay_eggs). it_is(carnivore) :- positive(does, eat_meat). it_is(carnivore) :-positive(has, pointed_teeth), positive(has, claws), positive(has, forward_eyes). it_is(ungulate) :- it_is(mammal), positive(has,

hooves). it_is(ungulate) :- it_is(mammal), positive(does,

chew_cud).

positive(X, Y) :- ask(X, Y, yes). negative(X, Y) :- ask(X, Y, no).

EX18EX01.pro : Animal (cont.)

Chapter 8 18344-302 LP and Prolog

ask(X, Y, yes) :- !, write(“Question > “, X, " it ", Y, “?”,’ \n’), readln(Reply), frontchar(Reply, 'y', _).

ask(X, Y, no) :- !, write(“Question > “,X, " it ", Y, “?”,’\n’), readln(Reply), frontchar(Reply, 'n', _).clear_facts :- write("\n\nPlease press the space bar to exit\n"), readchar(_).

run :- animal_is(X), !,

write("\nAnswer.... => Your animal may be a (an) ",X), nl, nl, clear_facts.

run :- write("\n Answer.... => Unable to determine what"), write("your animal is.\n\n"), clear_facts.

EX18EX01.pro : Animal (cont.)

Chapter 8 19344-302 LP and Prolog

Logic Programming

Propositional Predicate Logic

True False

Prolog

Fact Rule

pred_name(att1,att2,var1) if....then...

Expert System

VB

Symbolic

Chapter 8 20344-302 LP and Prolog

Turbo Prolog

domains predicates clauses

fact rule

Listinteger

stringsymbol

Symbolic

recursive

variable matching

pred_name(att1,att2,var1)

and, or, not

! cut, fail

+ - * / mod

interface

member appendreverse

read

factorial

write

window

head/tail length

goal

Chapter 8 21344-302 LP and Prolog

Expert System

Specific Domain User Interface Inference Engine

Fact Rule

if....then...

Artificial Intelligence

Explanation

Knowledge Engineer

Expert

Easy to use Tool

VBProlog Others

Symbolic Knowledge Representation

Chapter 8 22344-302 LP and Prolog

Knowledge Representation

semantic network

frame conceptual graph

slot

isa inheritant

Symbolic

predicate

Logic

pred_name(att1,att2)

Expert System

value

Chapter 8 23344-302 LP and Prolog

DEMO

EXPERT SYSTEMS