strength: fix is_terminal()

Fix #198.  Reported by Maximilien Colange.

* spot/twaalgos/strength.cc (is_terminal): Test that no accepting
transition lead to a rejecting SCC.
* tests/core/strength.test: Add test case.
* spot/twaalgos/strength.hh, spot/twa/twa.hh, doc/org/concepts.org:
Adjust documentation.
* NEWS: Mention the fix.
This commit is contained in:
Alexandre Duret-Lutz 2016-11-28 16:19:05 +01:00
parent f868e0cea6
commit 341eeb2ba1
6 changed files with 133 additions and 15 deletions

View file

@ -990,15 +990,15 @@ better choices.
There are actually several property flags that are stored into each
automaton, and that can be queried or set by algorithms:
| flag name | meaning when =true= |
|---------------------+---------------------------------------------------------------------------------------|
| =state_acc= | automaton should be considered has having state-based acceptance |
| =inherently_weak= | accepting and rejecting cycles cannot be mixed in the same SCC |
| =weak= | transitions of an SCC all belong to the same acceptance sets |
| =terminal= | automaton is weak, accepting SCCs are complete and may not reach rejecting cycles |
| =deterministic= | there is at most one run *recognizing* a word, but not necessarily accepting it |
| =unambiguous= | there is at most one run *accepting* a word (but it might be recognized several time) |
| =stutter_invariant= | the property recognized by the automaton is [[https://www.lrde.epita.fr/~adl/dl/adl/michaud.15.spin.pdf][stutter-invariant]] |
| flag name | meaning when =true= |
|---------------------+----------------------------------------------------------------------------------------------|
| =state_acc= | automaton should be considered has having state-based acceptance |
| =inherently_weak= | accepting and rejecting cycles cannot be mixed in the same SCC |
| =weak= | transitions of an SCC all belong to the same acceptance sets |
| =terminal= | automaton is weak, accepting SCCs are complete, accepting edges may not go to rejecting SCCs |
| =deterministic= | there is at most one run *recognizing* a word, but not necessarily accepting it |
| =unambiguous= | there is at most one run *accepting* a word (but it might be recognized several time) |
| =stutter_invariant= | the property recognized by the automaton is [[https://www.lrde.epita.fr/~adl/dl/adl/michaud.15.spin.pdf][stutter-invariant]] |
For each flag =flagname=, the =twa= class has a method
=prop_flagname()= that returns the value of the flag as an instance of