   so either self-crossing or not. However, for correct results using the
          overlay algorithms (intersection and difference algorithms in combination
          with a polygon) self-intersections can disturb the process and result in
          incorrect results.
        </p>
<h6>
<a name="geometry.reference.concepts.concept_linestring.h3"></a>
          <span class="phrase"><a name="geometry.reference.concepts.concept_linestring.available_models"></a></span><a class="link" href="concept_linestring.ht