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

description = '''\
<p><code>grandparent(P, C)</code>: <code>P</code> is a grandparent of <code>C</code>.</p>
<pre>
?- grandparent(tina, X).
  X = vanessa ;
  X = patricia.
?- grandparent(tina, vanessa).
  true.
</pre>'''

hint = {}