[Nauty] geng changes

[Brendan McKay]

* Sterten at aol.com <Sterten at aol.com> [021204 21:28]:
> geng changes

Ok, but don't call it geng.
 
> I included a count[n]++; in my PRUNE  subroutine in geng,
> and display the count[] values before geng exists.
> Then not only all graphs of size n are counted but
> also all graphs of smaller size.

There is no guarantee that all graphs smaller than the output
size are generated, so this is invalid.

> I want to remove the -t, -f switches, instead include a list
> of forbidden subgraphs or read a list of forbidden subgraphs from file.

However, -t, -f, -b are implemented much more efficiently than
is possible using PRUNE and should work correctly in conjunction
with PRUNE.  So removing them is a mistake.

Brendan.