+\anchor reversed_edges_helper_anchor
+<h2>Reversed Edges Helper</h2>
+
+\image html rev_edges_helper_dlg.png
+
+\b Helper group assists in defining <b>Reversed Edges</b>
+parameter of the hypotheses depending on edge direction.
+
+<b>Show whole geometry</b> check-box allows seeing the whole
+geometrical model in the 3D Viewer, which can help to understand the
+location of a set of edges within the model.
+
+<b>Propagation chains</b> group allows defining <b>Reversed Edges</b>
+for splitting opposite edges of quadrilateral faces
+in a logically uniform direction. When this group is
+activated, the list is filled with propagation chains found within the
+model. When a chain is selected in the list its edges are
+shown in the Viewer with arrows, which enables choosing a common
+direction for all chain edges. \b Reverse button inverts the common
+direction of chain edges. If \b Add button is active, some
+edges of a chain have a different direction, so you can click \b Add
+button to add them to <b>Reversed Edges</b> list.
+
+\image html propagation_chain.png "The whole geometry and a propagation chain"
+