evaluation of Automorphism on the standard basis is expensive
in hash(g::Automorphism, h::UInt) we
1. compute and store savedhash (evaluating f, if necessary) with a fixed value HASHINGCONST
2. xor h with savedhash
in == we evaluate f only at hash-colision (or when
This way we evaluate f multiple times only in ~2% of cases (for SAut(F_4))
kalmarek
7139322d05
