1.grandparent,brother,sister,ancestors program.

parent('sakib','rakib').
parent('swarna','momin').
parent('rakib','raju').
parent('sakib','jihad').

grandparent(X,Y):- parent(X,Z), parent(Z,Y).
brother(Y,Z):- parent(X,Y),parent(X,Z),not(Y=Z),male(Y).
sister(X,Y):- parent(Z,X),parent(Z,Y),not(X=Y), not(male(Y)).
ancestor(X,Y):- parent(X,Z), parent(X,A).

male('sakib').
male('rakib').
male('momin').
male('raju').
male('jihad').

2. Sum of number program.

sum(0,0).
sum(N,S):- N>0, N1 is N-1, sum(N1,S1), S is N+S1.

3. Oddsum program.

oddsum(0,0).
oddsum(N,F):- N>0, N1 is N-1, oddsum(N1,F1), F is (2*N-1)+F1.

4. Factorial number program.

fact(0,1).
fact(N,F):- N>0, N1 is N-1, fact(N1,F1), F is N*F1.

5. N number of sum.

nthsum(,,0,0).
nthsum(F,I,N,S):- N>0, N1 is N-1, nthsum(F,I,N1,S1), S is S1+I*(N-1)+F.

6. Loop program or desimal log.

go_loop1:- write('\nHow many computation?'),
         read(N), doloop1(N).

doloop1(0).
doloop1(N):- N>0, finddeslog, N1 is N-1, doloop1(N1).

finddeslog:- getposnum(X), Y is log10(X),
write('\nlog of'), write(X), write('is'),write(Y),write(.).

getposnum(X):- repeat,
write('\nEnter a positive number'),
read(X),X>0,!.