# $Id: tree.n3 1295 2007-05-11 16:52:51Z josd $
# PxButton | test  | python euler.py tree.n3
# PxButton | proof | python euler.py --why tree.n3

@prefix : <http://eulersharp.sourceforge.net/2005/11swap/tree#>.

:Frans :father :Jos.
:Maria :mother :Jos.
:Jos :father :Goedele.
:Jos :father :Veerle.
:Jos :father :Nele.
:Jos :father :Karel.
:Maaike :mother :Goedele.
:Maaike :mother :Veerle.
:Maaike :mother :Nele.
:Maaike :mother :Karel.

{?X :father ?Y} => {?X :parent ?Y}.
{?X :mother ?Y} => {?X :parent ?Y}.
{?Y :parent ?X} => {?X :childof ?Y}.
{?X :parent ?Y} => {?X :ancestor ?Y}.
{?X :ancestor ?Y. ?Y :ancestor ?Z} => {?X :ancestor ?Z}.
{?Y :ancestor ?X} => {?X :descendant ?Y}.

{:Frans :ancestor ?X} => [].
{:Veerle :descendant ?X} => [].