gap&gt; ps := PG(3,7);
ProjectiveSpace(3, 7)
gap&gt; planes := Planes(ps);
&lt;planes of ProjectiveSpace(3, 7)&gt;
gap&gt; iter := Iterator(planes);
&lt;iterator&gt;
gap&gt; NextIterator(iter);
&lt;a plane in ProjectiveSpace(3, 7)&gt;
gap&gt; IsDoneIterator(iter);
false
