1. Create a new Adobe Illustrator document.
2. Import the ukrail.gen file from the Tutorial Data folder and specify British National Grid as the coordinate system. It is located under Projected > Europe > United Kingdom.
3. Select all objects in the ukrail_line layer and click the Simplify Art button on the MAPublisher toolbar.
4. In the Simplify Art dialogue box, choose the Douglas-Peucker method, enter 2000 in the Proximity box and choose Meter in the Units drop-down list.
5. Click Preview to see a preview of the simplified data with the current settings.
Notice that the Simplify Art tool will simplify 17,186 vertices to 8,756 vertices (a vertex reduction of 50%.)
6. Click OK to start the simplification process.
The selected art is now simplified based on a proximity value of two kilometres (2000 meters)
7. Close the document without saving.