— Function File: sysadd (gsys, hsys)

returns sys = gsys + hsys.

• Exits with an error if gsys and hsys are not compatibly dimensioned.
• Prints a warning message is system states have identical names; duplicate names are given a suffix to make them unique.
• sys input/output names are taken from gsys.

          ________
          ----|  gsys  |---
          u   |    ----------  +|
          -----                (_)----> y
          |     ________   +|
          ----|  hsys  |---
          --------