Detection of Pin and Element Swaps.

After a circuit design has gone through schematic capture and the information sent to physical design, the physical design algorithms may exchange connections on equivalent pins or elements. These changes must be transferred back to the schematic. This document describes an algorithm for deducing these changes from the initial and changed connectivity lists. This algorithm has been implemented in the cmprdf and updrdf commands in Release 1.2 of SysCAD.