* spot/twaalgos/zlktree.cc (zielonka_tree): Find the models using a
recursive procedure on the acceptance condition, without conversion to
BDD.
* tests/python/_zlktree.ipynb: Adjust to a different order of nodes.
A quick and dirty implementation of the Alternating Cycle
Decomposition of the casares.21.icalp paper.
* spot/twaalgos/genem.cc, spot/twaalgos/genem.hh
(maximal_accepting_loops_for_scc): New function.
* spot/twaalgos/sccinfo.cc,
spot/twaalgos/sccinfo.hh (scc_and_mark_filter): Add a possibility to
specify a mask of transition to filter.
* spot/twaalgos/zlktree.hh, spot/twaalgos/zlktree.cc (acd): New class.
(acd_transform): New function.
* python/spot/__init__.py: Add SVG rendering for acd.
* tests/python/_zlktree.ipynb: Play with acd and acd_transform.
* tests/python/toparity.py: Add more tests to compare the
sizes of acd_transform and to_parity.
* NEWS: Mention this new feature.
* spot/twaalgos/zlktree.hh,
spot/twaalgos/zlktree.cc (zielonka_tree_transform): New function.
* tests/python/_zlktree.ipynb: Test it on three examples.
