In  it is shown that the ideas for computing
orbit representatives under the group action in form of ()
can be generalized for group actions in form of ().
You also have to compute the Sims-chain for the
group action GX. For finding short cuts in the minimality test
the following two facts are important:
Let f<(pj(i))-1 o f o pj(i),
and let f(i)<( (pj(i))-1 o f o pj(i))(i).
If furthermore f(j)£i-1 for all j£i-1 and f(i)£i,
then f<CG(i)((pj(i))-1 o f o pj(i)).
If f£CG(i)(f), and if there is some
sÎCG(i) such that
s o (pj(i))-1 o f o pj(i) o s-1=f, then
CG(i)((pj(i))-1 o f o pj(i))
last changed: January 23, 2001