The script flow.txt is the command sequence from the Alliance supplied
example. This is the unaltered Alliance design flow with some cosmetic
changes for file locations and names of catalogue files.

The final layout CIF and GDS files are missing implant layers (NIMP
and PIMP) because these aren't defined in the cmos.rds file.

The script find_crit_path has been added at the end to show the
critical paths with 0fF and 6fF wireload libraries. The timing
values are typical 0.35um, for which a 6fF wireload is very low.
A better value is 12fF.

                         0fF    6fF
Critical path delay is  2032   2120 ps
Area is                 8456   8456 um^2 (at lambda=0.5um)
Gate count                36     36
Occupancy                 80%    80%
