How to find the hcf using Visual Prolog programming

Visual prolog is a software of artificial intelligence(AI).Before  we start the programming in the visual prolog ,we should install the programand we must write the code in it.and the thing we should consider is wemust save thefile in .PRO file and be placed at the location where it is stored in C: drive.(C: VIP/BIN/WIN/32).

Here is the code  to find the HCF of two numbers in visual prolog:

%TO FIND THE HCF OF TWO NUMBERS



PREDICATES
hcf(integer, integer, integer)

CLAUSES
hcf(X, Y, X):-
Y mod X = 0.
hcf(X,Y,Z):-
S = Y mod X,S<>0, hcf(S, X, Z).

GOAL
hcf(5,10,X).

OUTPUT:
To find the output press the G button on the top of the software. the output of the above program looks like this

CONCEPT:
here the concept is that when the  number is divided exactly by  the smaller number or the divisor,then the divisor is the required hcf.
and if there is remainder in the division, then the hcf of the remainder and the previous divisor is found repeadtly until the remainder is 0,

in the above example,10 %5 is 0 so the HCF is 5.
in 20 and 30, 30%20=10
since remainder is not 0,we should find now HCF of 20 and 10 ,here remiander is 0.so HCF is 10.