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improve support for LTLf semantics

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* spot/twaalgos/remprop.cc, spot/twaalgos/remprop.hh (to_finite): New
function.
* bin/autfilt.cc (--to-finite): Add it.
* doc/org/tut12.org: Update to use it.
* spot/twa/twagraph.cc (purge_dead_states): Also remove false edges.
* spot/parseaut/parseaut.yy: Do not ignore false self-loops, and
add false self-loop on accepting states without successors.
* NEWS: List the above changes.
* tests/core/ltlf.test: New file.
* tests/Makefile.am: Add it.
* tests/core/complete.test: Adjust expected output.
This commit is contained in:
Alexandre Duret-Lutz 2022-02-07 14:44:04 +01:00
parent 9b0a20412b
commit a3753e608b
10 changed files with 416 additions and 83 deletions
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17
spot/parseaut/parseaut.yy
View file

@ -1379,6 +1379,13 @@ states: %empty
}
}
}
if (res.acc_state &&
!res.opts.want_kripke &&
res.h->aut->get_graph().state_storage(res.cur_state).succ == 0)
{
res.h->aut->new_edge(res.cur_state, res.cur_state,
bddfalse, res.acc_state);
}
}
state: state-name labeled-edges
| state-name unlabeled-edges
@ -1403,7 +1410,6 @@ state: state-name labeled-edges
{
res.h->ks->state_from_number(res.cur_state)->cond(res.state_label);
}
}
| error
{
@ -1412,6 +1418,8 @@ state: state-name labeled-edges
res.universal = spot::trival::maybe();
res.existential = spot::trival::maybe();
res.complete = spot::trival::maybe();
// also do not try to preserve any color
res.acc_state = {};
}
@ -1595,7 +1603,12 @@ incorrectly-unlabeled-edge: checked-state-num trans-acc_opt
}
labeled-edge: trans-label checked-state-num trans-acc_opt
{
if (res.cur_label != bddfalse)
if (res.cur_label != bddfalse ||
// As a hack to allow states to be accepting
// even if they do not have transitions, we
// do not ignore false-labeled self-loops if they
// have some colors)
($2 == res.cur_state && !!($3 | res.acc_state)))
{
if (res.opts.want_kripke)
res.h->ks->new_edge(res.cur_state, $2);

14
spot/twa/twagraph.cc
View file

@ -1,5 +1,5 @@
// -*- coding: utf-8 -*-
// Copyright (C) 2014-2021 Laboratoire de Recherche et Développement
// Copyright (C) 2014-2022 Laboratoire de Recherche et Développement
// de l'Epita.
//
// This file is part of Spot, a model checking library.
@ -713,8 +713,16 @@ namespace spot
bool useless = true;
while (t)
{
// An edge is useful if all its
// destinations are useful.
// Erase any false edge, except self-loops (which can
// be used to store colors on state without successor
// with state-based acceptance).
if (t->cond == bddfalse && t->src != t->dst)
{
t.erase();
continue;
}
// A non-false edge is useful if all its destinations
// are useful.
bool usefuledge = true;
for (unsigned d: univ_dests(t->dst))
if (!useful[d])

72
spot/twaalgos/remprop.cc
View file

@ -1,5 +1,5 @@
// -*- coding: utf-8 -*-
// Copyright (C) 2015-2019 Laboratoire de Recherche et Développement
// Copyright (C) 2015-2019, 2022 Laboratoire de Recherche et Développement
// de l'Epita (LRDE).
//
// This file is part of Spot, a model checking library.
@ -174,4 +174,74 @@ namespace spot
});
return res;
}
twa_graph_ptr to_finite(const_twa_graph_ptr aut, const char* alive)
{
twa_graph_ptr res =
make_twa_graph(aut,
{ false, false, true, false, false, false });
bdd rem = bddtrue;
bdd neg = bddfalse;
int v = res->get_dict()->
has_registered_proposition(spot::formula::ap(alive), aut);
if (v >= 0)
{
rem = bdd_ithvar(v);
neg = bdd_nithvar(v);
res->unregister_ap(v);
}
unsigned ns = res->num_states();
std::vector<bool> isacc(ns, false);
for (unsigned s = 0; s < ns; ++s)
{
for (auto& e: res->out(s))
if (bdd_implies(e.cond, neg))
{
isacc[e.src] = true;
e.cond = bddfalse;
}
else
{
e.cond = bdd_exist(e.cond, rem);
}
}
res->set_buchi();
res->prop_state_acc(true);
// Purge dead states will remove all states accessible via edges
// marked as "bddfalse" above, along with those edges.
auto old = new std::vector<unsigned>(ns);
std::iota(old->begin(), old->end(), 0);
res->set_named_prop("original-states", old);
res->purge_dead_states();
ns = res->num_states();
for (unsigned s = 0; s < ns; ++s)
{
if (isacc[(*old)[s]])
{
acc_cond::mark_t m = {0};
bool done = false;
for (auto& e: res->out(s))
{
e.acc = m;
done = true;
}
if (!done)
res->new_edge(s, s, bddfalse, m);
}
else
{
acc_cond::mark_t m = {};
for (auto& e: res->out(s))
e.acc = m;
}
}
return res;
}
}

17
spot/twaalgos/remprop.hh
View file

@ -1,5 +1,5 @@
// -*- coding: utf-8 -*-
// Copyright (C) 2015 Laboratoire de Recherche et Développement de
// Copyright (C) 2015, 2022 Laboratoire de Recherche et Développement de
// l'Epita (LRDE).
//
// This file is part of Spot, a model checking library.
@ -40,4 +40,19 @@ namespace spot
twa_graph_ptr strip(const_twa_graph_ptr aut) const;
};
/// \brief Interpret the "live" part of an automaton as finite automaton.
///
/// This functions assumes that there is a property "alive" is
/// that either true or false on all transitions, and that can only
/// switch from true to false.
///
/// Because Spot does not support finite automata, this creates a
/// state-based Büchi automaton where any states with a !alive
/// outgoing transition in the original automaton is accepting, and
/// all alive/!alive occurrences are removed.
SPOT_API twa_graph_ptr
to_finite(const_twa_graph_ptr aut, const char* alive = "alive");
}