twa: add support for very-weak property

* spot/twa/twa.hh: Implement the property.
* spot/parseaut/parseaut.yy, spot/twaalgos/hoa.cc: Add input
and output for it.
* spot/twaalgos/strength.cc,
spot/twaalgos/strength.hh (is_very_weak_automaton): New function.
* tests/core/alternating.test: Add a test for --check=strength
on an alternating automaton.
* tests/core/strength.test, tests/core/parseaut.test: Adjust expected
output.
* NEWS, doc/org/hoa.org, doc/org/concepts.org: Document it.
This commit is contained in:
Alexandre Duret-Lutz 2016-12-01 18:27:54 +01:00
parent a4ce999402
commit 582d455c23
11 changed files with 146 additions and 33 deletions

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@ -995,6 +995,7 @@ automaton, and that can be queried or set by algorithms:
| =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 |
| =very-weak= | weak automaton where all SCCs have size 1 |
| =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) |

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@ -603,10 +603,10 @@ body of the file, and then return and error if what has been declared
does not correspond to the reality.
Some supported properties (like =weak=, =inherently-weak=,
=unambiguous=, or =stutter-invariant=) are not double-checked, because
that would require more operations. Command-line tools that
read HOA files all take a =--trust-hoa=no= option to ignore properties
that are not double-checked by the parser.
=very-weak=, =terminal=, =unambiguous=, or =stutter-invariant=) are
not double-checked, because that would require more operations.
Command-line tools that read HOA files all take a =--trust-hoa=no=
option to ignore properties that are not double-checked by the parser.
It should be noted that each property can take three values: true,
false, or maybe. So actually two bits are used per property. For
@ -652,24 +652,25 @@ particular:
to detect deterministic automata that have been output by algorithms
that do not try to output deterministic automata.
| property | parser | stored | printer | notes |
|---------------------+---------+--------+---------------------------------------------+------------------------------------------------------------------|
| =state-labels= | checked | no | checked if =-Hk= | state labels are converted to transition labels when reading TωA |
| =trans-labels= | checked | no | always, unless =-Hi= or =-Hk= | |
| =implicit-labels= | checked | no | if =-Hi= | =-Hi= only works for deterministic automata |
| =explicit-labels= | checked | no | always, unless =-Hi= | |
| =state-acc= | checked | yes | checked, unless =-Ht= or =-Hm= | |
| =trans-acc= | checked | no | if not =state-acc= and not =-Hm= | |
| =no-univ-branch= | ignored | no | only if =-Hv= | |
| =deterministic= | checked | yes | checked | |
| =complete= | checked | no | checked | |
| =unambiguous= | trusted | yes | as stored if (=-Hv= or not =deterministic=) | can be checked with =--check=unambiguous= |
| =stutter-invariant= | trusted | yes | as stored | can be checked with =--check=stuttering= |
| =stutter-sensitive= | trusted | yes | as stored (opposite of =stutter-invariant=) | can be checked with =--check=stuttering= |
| =terminal= | trusted | yes | as stored | can be checked with =--check=strength= |
| =weak= | trusted | yes | as stored if (=-Hv= or not =terminal=) | can be checked with =--check=strength= |
| =inherently-weak= | trusted | yes | as stored if (=-Hv= or not =weak=) | can be checked with =--check=strength= |
| =colored= | ignored | no | checked | |
| property | parser | stored | printer | notes |
|---------------------+---------+--------+---------------------------------------------------------+------------------------------------------------------------------|
| =state-labels= | checked | no | checked if =-Hk= | state labels are converted to transition labels when reading TωA |
| =trans-labels= | checked | no | always, unless =-Hi= or =-Hk= | |
| =implicit-labels= | checked | no | if =-Hi= | =-Hi= only works for deterministic automata |
| =explicit-labels= | checked | no | always, unless =-Hi= | |
| =state-acc= | checked | yes | checked, unless =-Ht= or =-Hm= | |
| =trans-acc= | checked | no | if not =state-acc= and not =-Hm= | |
| =no-univ-branch= | ignored | no | only if =-Hv= | |
| =deterministic= | checked | yes | checked | |
| =complete= | checked | no | checked | |
| =unambiguous= | trusted | yes | as stored if (=-Hv= or not =deterministic=) | can be checked with =--check=unambiguous= |
| =stutter-invariant= | trusted | yes | as stored | can be checked with =--check=stuttering= |
| =stutter-sensitive= | trusted | yes | as stored (opposite of =stutter-invariant=) | can be checked with =--check=stuttering= |
| =terminal= | trusted | yes | as stored | can be checked with =--check=strength= |
| =very-weak= | trusted | yes | as stored if (=-Hv= or not =terminal=) | can be checked with =--check=strength= |
| =weak= | trusted | yes | as stored if (=-Hv= or not (=terminal= or =very-weak=)) | can be checked with =--check=strength= |
| =inherently-weak= | trusted | yes | as stored if (=-Hv= or not =weak=) | can be checked with =--check=strength= |
| =colored= | ignored | no | checked | |
The above table is for version 1 of the format. When version 1.1 is
selected (using =-H1.1=), some negated properties may be output. In