ing a user defined polygon class to the library polygon_concept</li>
            <li><a href="gtl_polygon_set_usage.htm">polygon_set_usage.cpp</a>
Using the library provided polygon set data types and functions</li>
            <li><a href="gtl_custom_polygon_set.htm">custom_polygon_set.cpp</a>
Mapping a user defined class to the library polygon_set_concept</li>
            <li><a href="gtl_connectivity_extraction_usage.htm">connectivity_extraction_usage.cpp</a>
Using the connectivity extraction algorithm t