Function:      GDSC_INTERSECT

Purpose:       return the intersection coordinate word of two subsets

Category:      GDS

File:          gdsc_intersect.c

Author:        W. Zwitser

Use:           INTEGER  GDSC_INTERSECT( SET,           Input       character
                                        SUBSET_1       Input       integer
                                        SUBSET_2       Input       integer
                                        ERROR )        In/Out      integer

               GDSC_INTERSECT  Returns coordinate word of intersecting
                               sub structure or -1 if sub structures do
                               not intersect.

               SET             set name
               
               SUBSET_1        coordinate word of subset 1 

               SUBSET_2        coordinate word of subset 2 

               ERROR           0 = successful
                              <0 = a GDS error

Updates:       Mar  1, 1990: WZ, migrated to C.
               Oct 31, 1990: WZ, 'naxis', etc. from setsta -> dsc_file.
               Aug  3, 1991: KGB, Returns -1 for no intersection.
               Mar 24, 1994: JPT, modified to cooperate with GDS server.