Index: TRBS/trbs.html
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--- TRBS/trbs.html	(revision 539)
+++ TRBS/trbs.html	(revision 540)
@@ -123,7 +123,12 @@
 	     placed earlier); visibility is calucated as described below, in
 	     section V.
 </ul>
+<p>
+The cost function is path length assuming edge crossing points are located
+at where they result in the shortest path, ignoring wire widths and
+clearances. The heuristic function is the distance to the 2net's ending vertex.
 
+
 <h2> V. TRBS algorithm: query in-triangle visibility </h2>
 <p>
 The path is entering a triangle from a vertex or from a specific point on