%% Sample assertions for a family.  We'll asume that we make explicit
%%  assertions about four predicates: male/1, female/1, parent/2 and
%%  spouse/2.

% assert that these predicates are dynamic so that we can add new
% assertions interactively.

:- dynamic male/1, female/1, parent/2, spouse/2.

male(william).
male(peter).
male(bob).
male(jerry).
male(cormac).

female(carol).
female(katie).
female(clare).
female(dorothy).
female(hope).

parent(william,katie).
parent(william,peter).
parent(william,clare).
parent(tom,william).
parent(dorothy,william).
parent(tom,carol).
parent(dorothy,carol).
parent(carol,julia).
parent(carol,laura).
parent(katie,cormac).
parent(jerry,cormac).

spouse(hope,william).
spouse(william,hope).
spouse(carol,bob).
spouse(bob,carol).
spouse(jerry,katie).
spouse(katie,jerry).