sympy/sympy — pull request #1562 by pernici (2012-10-09 08:43:47+00:00)
Title: replaced the schreier_sims method with Jerrum filter with the incremental one

Eliminated the `schreier_sims` method with
the `Jerrum` filter, because it is asymptotically slower than `schreier_sims_incremental`,
and in some case stalls, e.g. with RubikGroup(4).

Eliminated `_stabilizer_cosets`, `_stabilizer_cosets_n` which duplicate
the data in `_transversals.`
Eliminated the `stabilizer_cosets` method.

The above changes do not make a difference in the speeds of the tests.

The previous commits are trivial speedups; now the tests run 1.6 times faster on my computer.