# coding=utf-8

name = 'ancestor/2'
slug = 'the ancestor relation'

description = '''\
<p><code>ancestor(X, Y)</code>: <code>X</code> is an ancestor (parent, grandparent,...) of <code>Y</code>.</p>
<pre>
  ?- ancestor(patricia, X).
    X = john ;
    X = michael ;
    X = michelle.
</pre>'''

hint = {}