%	Database of family relationships.
mother(geoff, dorothy).
mother(graham, dorothy).
mother(barbara, dorothy).
mother(chris, barbara).
mother(lucette, barbara).
mother(jasmine, barbara).
mother(jay, barbara).
mother(david, ruth).
mother(elizabeth, ruth).
mother(rob, annie).
mother(henry, annie).
mother(norman, annie).
mother(perce, annie).
mother(ben, annie).
mother(marion, annie).
mother(winnie, annie).
mother(ivy, annie).
mother(lil, annie).
mother(nina, annie).
mother(rita, annie).
mother(pauline, annie).
mother(andrea, blanche).
mother(norma, ethel).
mother(ruth, ethel).
mother(rosslyn, norma).
mother(lance, winnifred).
mother(normanH, winnifred).
mother(ray, winnifred).
mother(ena, winnifred).
mother(winK, winnifred).
mother(dorothy, winnifred).

sex(geoff, male).
sex(graham, male).
sex(barbara, female).
sex(chris, male).
sex(lucette, female).
sex(jasmine, female).
sex(jay, female).
sex(david, male).
sex(elizabeth, female).
sex(rob, male).
sex(henry, male).
sex(norman, male).
sex(perce, male).
sex(ben, male).
sex(marion, female).
sex(winnie, female).
sex(ivy, female).
sex(lil, female).
sex(nina, female).
sex(rita, female).
sex(pauline, female).
sex(andrea, female).
sex(norma, female).
sex(ruth, female).
sex(rosslyn, female).
sex(lance, male).
sex(normanH, male).
sex(ray, male).
sex(ena, female).
sex(winK, female).
sex(dorothy, female).
father(geoff, norman).
father(graham, norman).
father(barbara, norman).
father(chris, leon).
father(lucette, leon).
father(jasmine, leon).
father(jay, leon).
father(david, graham).
father(elizabeth, graham).
father(rob, robert).
father(henry, robert).
father(norman, robert).
father(perce, robert).
father(ben, robert).
father(marion, robert).
father(winnie, robert).
father(ivy, robert).
father(lil, robert).
father(nina, robert).
father(rita, robert).
father(pauline, robert).
father(andrea, geoff).
father(norma, dave).
father(ruth, dave).
father(rosslyn, ron).
father(lance, george).
father(normanH, george).
father(ray, george).
father(ena, george).
father(winK, george).
father(dorothy, george).

child(X, Y) :- father(Y, X).
child(X, Y) :- mother(Y, X).

son(X, Y) :-
	child(X, Y),
	sex(Y, male).

daughter(X, Y) :-
	child(X, Y),
	sex(Y, female).

siblings(X, Y) :- father(X, Z), father(Y, Z).
siblings(X, Y) :- mother(X, Z), mother(Y, Z).

brother(X, Y) :-
	siblings(X, Y),
	X /= Y,
	sex(Y, male).

sister(X, Y) :-
	siblings(X, Y),
	X /= Y,
	sex(Y, female).
