gap&gt; ps := PG(2,27);
ProjectiveSpace(2, 27)
gap&gt; sub := VectorSpaceToElement(ps,[[1,0,1,],[0,1,0]]*Z(3)^0);
&lt;a line in ProjectiveSpace(2, 27)&gt;
gap&gt; p := VectorSpaceToElement(ps,[1,0,2]*Z(3)^0);
&lt;a point in ProjectiveSpace(2, 27)&gt;
gap&gt; g := ProjectiveHomologyGroup(sub,p);
&lt;projective collineation group with 1 generators&gt;
gap&gt; Order(g);
26
gap&gt; StructureDescription(g);
"C26"
