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hierarchy: Add is_persistence() and make is_recurrence() use it

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* NEWS: Update.
* bin/man/spot-x.x: Add environment variable.
* spot/tl/hierarchy.cc: Implement them.
* spot/tl/hierarchy.hh: Declare them.
This commit is contained in:
Alexandre GBAGUIDI AISSE 2017-07-28 13:28:09 +02:00
parent e59274b609
commit c827f75c37
4 changed files with 208 additions and 28 deletions
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159
spot/tl/hierarchy.cc
View file

@ -26,34 +26,149 @@
#include <spot/twaalgos/remfin.hh>
#include <spot/twaalgos/strength.hh>
#include <spot/twaalgos/totgba.hh>
#include <spot/twaalgos/cobuchi.hh>
namespace spot
{
bool
is_recurrence(formula f, const twa_graph_ptr& aut)
namespace
{
if (f.is_syntactic_recurrence() || is_universal(aut))
return true;
// If aut is a non-deterministic TGBA, we do
// TGBA->DPA->DRA->(D?)BA. The conversion from DRA to
// BA will preserve determinism if possible.
spot::postprocessor p;
p.set_type(spot::postprocessor::Generic);
p.set_pref(spot::postprocessor::Deterministic
| spot::postprocessor::SBAcc);
p.set_level(spot::postprocessor::Low);
auto dra = p.run(aut);
if (dra->acc().is_generalized_buchi())
{
static bool
cobuchi_realizable(spot::formula f,
const const_twa_graph_ptr& aut)
{
twa_graph_ptr cobuchi = nullptr;
std::vector<acc_cond::rs_pair> pairs;
if (aut->acc().is_streett_like(pairs) || aut->acc().is_parity())
cobuchi = nsa_to_dca(aut, false);
else if (aut->get_acceptance().is_dnf())
cobuchi = dnf_to_dca(aut, false);
else
throw std::runtime_error("cobuchi_realizable() only works with "
"Streett-like, Parity or any "
"acceptance condition in DNF");
return !cobuchi->intersects(ltl_to_tgba_fm(formula::Not(f),
cobuchi->get_dict(),
true));
}
static bool
detbuchi_realizable(const twa_graph_ptr& aut)
{
if (is_universal(aut))
return true;
// if aut is a non-deterministic TGBA, we do
// TGBA->DPA->DRA->(D?)BA. The conversion from DRA to
// BA will preserve determinism if possible.
spot::postprocessor p;
p.set_type(spot::postprocessor::Generic);
p.set_pref(spot::postprocessor::Deterministic);
p.set_level(spot::postprocessor::Low);
auto dra = p.run(aut);
if (dra->acc().is_generalized_buchi())
{
assert(is_deterministic(dra));
return true;
}
else
{
auto ba = rabin_to_buchi_maybe(to_generalized_rabin(dra));
assert(ba);
return is_deterministic(ba);
}
}
}
static prcheck
algo_to_perform(bool is_persistence, bool aut_given, prcheck algo)
{
if (algo == prcheck::PR_Auto)
{
// Check environment variable.
static int val_s = []()
{
try
{
auto s = getenv("SPOT_PR_CHECK");
return s ? std::stoi(s) : 0;
}
catch (const std::exception& e)
{
throw std::runtime_error("invalid value for SPOT_PR_CHECK "
"(should be 1 or 2)");
}
}();
if (val_s == 1)
{
return prcheck::PR_via_CoBuchi;
}
else if (val_s == 2)
{
return prcheck::PR_via_Rabin;
}
else if (!val_s)
{
if (aut_given && !is_persistence)
return prcheck::PR_via_Rabin;
else if ((aut_given && is_persistence) || !aut_given)
return prcheck::PR_via_CoBuchi;
else
SPOT_UNREACHABLE();
}
else
SPOT_UNREACHABLE();
}
else
{
auto ba = rabin_to_buchi_maybe(to_generalized_rabin(dra));
assert(ba);
return is_deterministic(ba);
}
return algo;
}
bool
is_persistence(formula f, twa_graph_ptr aut, prcheck algo)
{
if (f.is_syntactic_persistence())
return true;
switch (algo_to_perform(true, aut != nullptr, algo))
{
case prcheck::PR_via_CoBuchi:
return cobuchi_realizable(f,
aut ? aut : ltl_to_tgba_fm(f, make_bdd_dict(), true));
case prcheck::PR_via_Rabin:
return detbuchi_realizable(
ltl_to_tgba_fm(formula::Not(f), make_bdd_dict(), true));
case prcheck::PR_Auto:
SPOT_UNREACHABLE();
}
SPOT_UNREACHABLE();
}
bool
is_recurrence(formula f, twa_graph_ptr aut, prcheck algo)
{
if (f.is_syntactic_recurrence())
return true;
switch (algo_to_perform(false, aut != nullptr, algo))
{
case prcheck::PR_via_CoBuchi:
return cobuchi_realizable(formula::Not(f),
ltl_to_tgba_fm(formula::Not(f), make_bdd_dict(), true));
case prcheck::PR_via_Rabin:
return detbuchi_realizable(
aut ? aut : ltl_to_tgba_fm(f, make_bdd_dict(), true));
case prcheck::PR_Auto:
SPOT_UNREACHABLE();
}
SPOT_UNREACHABLE();
}
char mp_class(formula f)
@ -78,9 +193,7 @@ namespace spot
// Not an obligation. Could by 'P', 'R', or 'T'.
if (is_recurrence(f, aut))
return 'R';
f = formula::Not(f);
aut = ltl_to_tgba_fm(f, dict, true);
if (is_recurrence(f, aut))
if (is_persistence(f, aut))
return 'P';
return 'T';
}