The files for 1syst (FILTER) should be analyzed in the following sequence:

ELEMpack.vhd
GateLib.vhd

MULTpack.vhd
MULTcell.vhd
MULTstruc.vhd

FILTERpack.vhd
FILTERcra.vhd
FILTERstage.vhd
FILTERstruc.vhd


While using the SYNOPSYS Design Analyzer V3.1a, you might want to use 
the Filter.script for fast reading and synthesis without failures.
Please note, that the required directory structure is:
      /SYNOPSYS
      /SYNOPSYS/WORK
      /SYNOPSYS/FILTER (DA should be started from here)
      /SYNOPSYS/MULTIPLIER