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Add a new form of TA with a Single-pass emptiness check (STA)

Browse source 
* src/ta/ta.cc, src/ta/ta.hh, src/ta/taexplicit.cc,
src/ta/taexplicit.hh, src/ta/taproduct.cc,src/ta/taproduct.hh,
src/taalgos/dotty.cc, src/taalgos/emptinessta.cc,
src/taalgos/emptinessta.hh, src/taalgos/minimize.cc,
src/taalgos/reachiter.cc, src/taalgos/sba2ta.cc, src/taalgos/sba2ta.hh,
src/tgbatest/ltl2ta.test, src/tgbatest/ltl2tgba.cc: Impacts of the
implementation of a new variant of TA, called STA, which involve a
Single-pass emptiness check. The new options (-in and -lv) added to
build the new variants of TA allow to add two artificial states:
1- an initial artificial state to have an unique initial state (-in)
2- a livelock artificial state which has no successors in order to
obtain the new form of TA which requires only a Single-pass emptiness-
check: STA (-lv).
This commit is contained in:
Ala-Eddine Ben-Salem 2011-05-17 23:41:45 +02:00 • committed by Alexandre Duret-Lutz
parent 310973f88c
commit 782ba0010b
15 changed files with 1224 additions and 711 deletions
Download patch file Download diff file Expand all files Collapse all files

19
src/taalgos/dotty.cc
View file

@ -43,10 +43,24 @@ namespace spot
os_ << "digraph G {" << std::endl;
int n = 0;
const ta::states_set_t init_states_set =
t_automata_->get_initial_states_set();
spot::state* artificial_initial_state =
t_automata_->get_artificial_initial_state();
ta::states_set_t init_states_set;
ta::states_set_t::const_iterator it;
if (artificial_initial_state != 0)
{
init_states_set.insert(artificial_initial_state);
}
else
{
init_states_set = t_automata_->get_initial_states_set();
}
for (it = (init_states_set.begin()); it != init_states_set.end(); it++)
{
// cout << (*it).first << " => " << (*it).second << endl;
@ -60,6 +74,7 @@ namespace spot
+ "\"]" << std::endl;
}
}
void

709
src/taalgos/emptinessta.cc
View file

@ -18,7 +18,7 @@
// Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
// 02111-1307, USA.
// #define TRACE
//#define TRACE
#include <iostream>
#ifdef TRACE
@ -34,7 +34,7 @@
namespace spot
{
ta_check::ta_check(const ta* a, option_map o) :
ta_check::ta_check(const ta_product* a, option_map o) :
a_(a), o_(o)
{
is_full_2_pass_ = o.get("is_full_2_pass", 0);
@ -46,7 +46,7 @@ namespace spot
}
bool
ta_check::check()
ta_check::check(bool disable_second_pass)
{
// We use five main data in this algorithm:
@ -54,7 +54,7 @@ namespace spot
// * h: a hash of all visited nodes, with their order,
// (it is called "Hash" in Couvreur's paper)
numbered_state_heap* h =
numbered_state_heap_hash_map_factory::instance()->build(); ///< Heap of visited states.
numbered_state_heap_hash_map_factory::instance()->build(); ///< Heap of visited states.
// * num: the number of visited nodes. Used to set the order of each
// visited node,
@ -71,276 +71,291 @@ namespace spot
std::stack<spot::state*> init_set;
Sgi::hash_map<const state*, std::string, state_ptr_hash, state_ptr_equal>
colour;
colour;
trace
<< "PASS 1" << std::endl;
//const std::string WHITE = "W";
//const std::string GREY = "G";
//const std::string BLUE = "B";
//const std::string BLACK = "BK";
Sgi::hash_map<const state*, std::set<const state*, state_ptr_less_than>,
state_ptr_hash, state_ptr_equal> liveset;
state_ptr_hash, state_ptr_equal> liveset;
std::stack<spot::state*> livelock_roots;
bool livelock_acceptance_states_not_found = true;
const ta::states_set_t init_states_set = a_->get_initial_states_set();
ta::states_set_t::const_iterator it;
for (it = init_states_set.begin(); it != init_states_set.end(); it++)
{
state* init_state = (*it);
init_set.push(init_state);
//colour[init_state] = WHITE;
state* init_state = (*it);
init_set.push(init_state);
}
while (!init_set.empty())
{
// Setup depth-first search from initial states.
// Setup depth-first search from initial states.
{
state* init = init_set.top();
init_set.pop();
{
state* init = init_set.top();
init_set.pop();
numbered_state_heap::state_index_p h_init = h->find(init);
numbered_state_heap::state_index_p h_init = h->find(init);
if (h_init.first)
continue;
if (h_init.first)
continue;
h->insert(init, ++num);
scc.push(num);
h->insert(init, ++num);
scc.push(num);
ta_succ_iterator* iter = a_->succ_iter(init);
iter->first();
todo.push(pair_state_iter(init, iter));
//colour[init] = GREY;
inc_depth();
ta_succ_iterator* iter = a_->succ_iter(init);
iter->first();
todo.push(pair_state_iter(init, iter));
//push potential root of live-lock accepting cycle
if (a_->is_livelock_accepting_state(init))
livelock_roots.push(init);
inc_depth();
}
//push potential root of live-lock accepting cycle
if (a_->is_livelock_accepting_state(init))
livelock_roots.push(init);
while (!todo.empty())
{
}
state* curr = todo.top().first;
while (!todo.empty())
{
// We are looking at the next successor in SUCC.
ta_succ_iterator* succ = todo.top().second;
state* curr = todo.top().first;
// If there is no more successor, backtrack.
if (succ->done())
{
// We have explored all successors of state CURR.
// We are looking at the next successor in SUCC.
ta_succ_iterator* succ = todo.top().second;
// If there is no more successor, backtrack.
if (succ->done())
{
// We have explored all successors of state CURR.
// Backtrack TODO.
todo.pop();
dec_depth();
trace
<< "PASS 1 : backtrack" << std::endl;
// Backtrack TODO.
todo.pop();
dec_depth();
trace
<< "PASS 1 : backtrack" << std::endl;
// fill rem with any component removed,
numbered_state_heap::state_index_p spi =
h->index(curr->clone());
assert(spi.first);
if (a_->is_livelock_accepting_state(curr))
{
livelock_acceptance_states_not_found = false;
trace
<< "PASS 1 : livelock accepting state found" << std::endl;
scc.rem().push_front(curr);
inc_depth();
}
// set the h value of the Backtracked state to negative value.
// colour[curr] = BLUE;
*spi.second = -std::abs(*spi.second);
// fill rem with any component removed,
numbered_state_heap::state_index_p spi =
h->index(curr->clone());
assert(spi.first);
// Backtrack livelock_roots.
if (!livelock_roots.empty() && !livelock_roots.top()->compare(
curr))
livelock_roots.pop();
scc.rem().push_front(curr);
inc_depth();
// When backtracking the root of an SSCC, we must also
// remove that SSCC from the ROOT stacks. We must
// discard from H all reachable states from this SSCC.
assert(!scc.empty());
if (scc.top().index == std::abs(*spi.second))
{
// removing states
std::list<state*>::iterator i;
// set the h value of the Backtracked state to negative value.
// colour[curr] = BLUE;
*spi.second = -std::abs(*spi.second);
for (i = scc.rem().begin(); i != scc.rem().end(); ++i)
{
numbered_state_heap::state_index_p spi = h->index(
(*i)->clone());
assert(spi.first->compare(*i) == 0);
assert(*spi.second != -1);
*spi.second = -1;
//colour[*i] = BLACK;
// Backtrack livelock_roots.
if (!livelock_roots.empty() && !livelock_roots.top()->compare(
curr))
livelock_roots.pop();
}
dec_depth(scc.rem().size());
scc.pop();
}
// When backtracking the root of an SSCC, we must also
// remove that SSCC from the ROOT stacks. We must
// discard from H all reachable states from this SSCC.
assert(!scc.empty());
if (scc.top().index == std::abs(*spi.second))
{
// removing states
std::list<state*>::iterator i;
delete succ;
// Do not delete CURR: it is a key in H.
continue;
}
for (i = scc.rem().begin(); i != scc.rem().end(); ++i)
{
numbered_state_heap::state_index_p spi = h->index(
(*i)->clone());
assert(spi.first->compare(*i) == 0);
assert(*spi.second != -1);
*spi.second = -1;
//colour[*i] = BLACK;
// We have a successor to look at.
inc_transitions();
trace
<< "PASS 1: transition" << std::endl;
// Fetch the values destination state we are interested in...
state* dest = succ->current_state();
}
dec_depth(scc.rem().size());
scc.pop();
}
//may be Buchi accepting scc
scc.top().is_accepting = a_->is_accepting_state(curr)
&& !succ->is_stuttering_transition();
delete succ;
// Do not delete CURR: it is a key in H.
continue;
}
bool is_stuttering_transition = succ->is_stuttering_transition();
// We have a successor to look at.
inc_transitions();
trace
<< "PASS 1: transition" << std::endl;
// Fetch the values destination state we are interested in...
state* dest = succ->current_state();
// ... and point the iterator to the next successor, for
// the next iteration.
succ->next();
// We do not need SUCC from now on.
bool curr_is_livelock_hole_state_in_ta_component =
(a_->is_hole_state_in_ta_component(curr))
&& a_->is_livelock_accepting_state(curr);
// Are we going to a new state?
numbered_state_heap::state_index_p spi = h->find(dest);
//may be Buchi accepting scc or livelock accepting state (contains a TA hole and livelock accepting state)
scc.top().is_accepting = (a_->is_accepting_state(curr)
&& !succ->is_stuttering_transition())
|| curr_is_livelock_hole_state_in_ta_component;
// Is this a new state?
if (!spi.first)
{
// Number it, stack it, and register its successors
// for later processing.
h->insert(dest, ++num);
scc.push(num);
bool is_stuttering_transition = succ->is_stuttering_transition();
ta_succ_iterator* iter = a_->succ_iter(dest);
iter->first();
todo.push(pair_state_iter(dest, iter));
//colour[dest] = GREY;
inc_depth();
// ... and point the iterator to the next successor, for
// the next iteration.
succ->next();
// We do not need SUCC from now on.
//push potential root of live-lock accepting cycle
if (a_->is_livelock_accepting_state(dest)
&& !is_stuttering_transition)
livelock_roots.push(dest);
// Are we going to a new state?
numbered_state_heap::state_index_p spi = h->find(dest);
continue;
}
// Is this a new state?
if (!spi.first)
{
// Number it, stack it, and register its successors
// for later processing.
h->insert(dest, ++num);
scc.push(num);
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
continue;
ta_succ_iterator* iter = a_->succ_iter(dest);
iter->first();
todo.push(pair_state_iter(dest, iter));
//colour[dest] = GREY;
inc_depth();
// Now this is the most interesting case. We have reached a
// state S1 which is already part of a non-dead SSCC. Any such
// non-dead SSCC has necessarily been crossed by our path to
// this state: there is a state S2 in our path which belongs
// to this SSCC too. We are going to merge all states between
// this S1 and S2 into this SSCC.
//
// This merge is easy to do because the order of the SSCC in
// ROOT is ascending: we just have to merge all SSCCs from the
// top of ROOT that have an index greater to the one of
// the SSCC of S2 (called the "threshold").
int threshold = std::abs(*spi.second);
std::list<state*> rem;
bool acc = false;
//push potential root of live-lock accepting cycle
if (a_->is_livelock_accepting_state(dest)
&& !is_stuttering_transition)
livelock_roots.push(dest);
while (threshold < scc.top().index)
{
assert(!scc.empty());
continue;
}
acc |= scc.top().is_accepting;
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
continue;
rem.splice(rem.end(), scc.rem());
scc.pop();
// Now this is the most interesting case. We have reached a
// state S1 which is already part of a non-dead SSCC. Any such
// non-dead SSCC has necessarily been crossed by our path to
// this state: there is a state S2 in our path which belongs
// to this SSCC too. We are going to merge all states between
// this S1 and S2 into this SSCC.
//
// This merge is easy to do because the order of the SSCC in
// ROOT is ascending: we just have to merge all SSCCs from the
// top of ROOT that have an index greater to the one of
// the SSCC of S2 (called the "threshold").
int threshold = std::abs(*spi.second);
std::list<state*> rem;
bool acc = false;
}
// Note that we do not always have
// threshold == scc.top().index
// after this loop, the SSCC whose index is threshold might have
// been merged with a lower SSCC.
while (threshold < scc.top().index)
{
assert(!scc.empty());
// Accumulate all acceptance conditions into the merged SSCC.
scc.top().is_accepting |= acc;
acc |= scc.top().is_accepting;
scc.rem().splice(scc.rem().end(), rem);
if (scc.top().is_accepting)
{
clear(h, todo, init_set);
trace
<< "PASS 1: SUCCESS" << std::endl;
return true;
}
rem.splice(rem.end(), scc.rem());
scc.pop();
//ADDLINKS
if (!is_full_2_pass_ && a_->is_livelock_accepting_state(curr)
&& is_stuttering_transition)
{
trace
<< "PASS 1: heuristic livelock detection " << std::endl;
const state* dest = spi.first;
std::set<const state*, state_ptr_less_than> liveset_dest =
liveset[dest];
}
// Note that we do not always have
// threshold == scc.top().index
// after this loop, the SSCC whose index is threshold might have
// been merged with a lower SSCC.
std::set<const state*, state_ptr_less_than> liveset_curr =
liveset[curr];
// Accumulate all acceptance conditions into the merged SSCC.
scc.top().is_accepting |= acc;
int h_livelock_root = 0;
if (!livelock_roots.empty())
h_livelock_root = *(h->find((livelock_roots.top()))).second;
scc.rem().splice(scc.rem().end(), rem);
if (scc.top().is_accepting)
{
clear(h, todo, init_set);
trace
<< "PASS 1: SUCCESS" << std::endl;
return true;
}
if (heuristic_livelock_detection(dest, h, h_livelock_root,
liveset_curr))
{
clear(h, todo, init_set);
return true;
}
//ADDLINKS
if (!is_full_2_pass_ && a_->is_livelock_accepting_state(curr)
&& is_stuttering_transition)
{
trace
<< "PASS 1: heuristic livelock detection " << std::endl;
const state* dest = spi.first;
std::set<const state*, state_ptr_less_than> liveset_dest =
liveset[dest];
std::set<const state*, state_ptr_less_than>::const_iterator it;
for (it = liveset_dest.begin(); it != liveset_dest.end(); it++)
{
const state* succ = (*it);
if (heuristic_livelock_detection(succ, h, h_livelock_root,
liveset_curr))
{
clear(h, todo, init_set);
return true;
}
std::set<const state*, state_ptr_less_than> liveset_curr =
liveset[curr];
}
int h_livelock_root = 0;
if (!livelock_roots.empty())
h_livelock_root = *(h->find((livelock_roots.top()))).second;
}
}
if (heuristic_livelock_detection(dest, h, h_livelock_root,
liveset_curr))
{
clear(h, todo, init_set);
return true;
}
std::set<const state*, state_ptr_less_than>::const_iterator it;
for (it = liveset_dest.begin(); it != liveset_dest.end(); it++)
{
const state* succ = (*it);
if (heuristic_livelock_detection(succ, h, h_livelock_root,
liveset_curr))
{
clear(h, todo, init_set);
return true;
}
}
}
}
}
clear(h, todo, init_set);
if (disable_second_pass || livelock_acceptance_states_not_found)
return false;
return livelock_detection(a_);
}
bool
ta_check::heuristic_livelock_detection(const state * u,
numbered_state_heap* h, int h_livelock_root, std::set<const state*,
state_ptr_less_than> liveset_curr)
state_ptr_less_than> liveset_curr)
{
numbered_state_heap::state_index_p hu = h->find(u);
if (*hu.second > 0) // colour[u] == GREY
{
if (*hu.second >= h_livelock_root)
{
trace
<< "PASS 1: heuristic livelock detection SUCCESS" << std::endl;
return true;
}
if (*hu.second >= h_livelock_root)
{
trace
<< "PASS 1: heuristic livelock detection SUCCESS" << std::endl;
return true;
}
liveset_curr.insert(u);
liveset_curr.insert(u);
}
return false;
@ -358,7 +373,7 @@ namespace spot
// * h: a hash of all visited nodes, with their order,
// (it is called "Hash" in Couvreur's paper)
numbered_state_heap* h =
numbered_state_heap_hash_map_factory::instance()->build(); ///< Heap of visited states.
numbered_state_heap_hash_map_factory::instance()->build(); ///< Heap of visited states.
// * num: the number of visited nodes. Used to set the order of each
// visited node,
@ -378,195 +393,191 @@ namespace spot
// * init: the set of the depth-first search initial states
std::stack<spot::state*> init_set;
const ta::states_set_t init_states_set = a_->get_initial_states_set();
ta::states_set_t::const_iterator it;
for (it = init_states_set.begin(); it != init_states_set.end(); it++)
{
state* init_state = (*it);
init_set.push(init_state);
state* init_state = (*it);
init_set.push(init_state);
}
while (!init_set.empty())
{
// Setup depth-first search from initial states.
{
state* init = init_set.top();
init_set.pop();
numbered_state_heap::state_index_p h_init = h->find(init);
// Setup depth-first search from initial states.
{
state* init = init_set.top();
init_set.pop();
numbered_state_heap::state_index_p h_init = h->find(init);
if (h_init.first)
continue;
if (h_init.first)
continue;
h->insert(init, ++num);
sscc.push(num);
sscc.top().is_accepting = t->is_livelock_accepting_state(init);
ta_succ_iterator* iter = t->succ_iter(init);
iter->first();
todo.push(pair_state_iter(init, iter));
inc_depth();
h->insert(init, ++num);
sscc.push(num);
sscc.top().is_accepting = t->is_livelock_accepting_state(init);
ta_succ_iterator* iter = t->succ_iter(init);
iter->first();
todo.push(pair_state_iter(init, iter));
inc_depth();
}
}
while (!todo.empty())
{
while (!todo.empty())
{
state* curr = todo.top().first;
state* curr = todo.top().first;
// We are looking at the next successor in SUCC.
ta_succ_iterator* succ = todo.top().second;
// We are looking at the next successor in SUCC.
ta_succ_iterator* succ = todo.top().second;
// If there is no more successor, backtrack.
if (succ->done())
{
// We have explored all successors of state CURR.
// If there is no more successor, backtrack.
if (succ->done())
{
// We have explored all successors of state CURR.
// Backtrack TODO.
todo.pop();
dec_depth();
trace
<< "PASS 2 : backtrack" << std::endl;
// Backtrack TODO.
todo.pop();
dec_depth();
trace
<< "PASS 2 : backtrack" << std::endl;
// fill rem with any component removed,
numbered_state_heap::state_index_p spi =
h->index(curr->clone());
assert(spi.first);
// fill rem with any component removed,
numbered_state_heap::state_index_p spi =
h->index(curr->clone());
assert(spi.first);
sscc.rem().push_front(curr);
inc_depth();
sscc.rem().push_front(curr);
inc_depth();
// When backtracking the root of an SSCC, we must also
// remove that SSCC from the ROOT stacks. We must
// discard from H all reachable states from this SSCC.
assert(!sscc.empty());
if (sscc.top().index == *spi.second)
{
// removing states
std::list<state*>::iterator i;
// When backtracking the root of an SSCC, we must also
// remove that SSCC from the ROOT stacks. We must
// discard from H all reachable states from this SSCC.
assert(!sscc.empty());
if (sscc.top().index == *spi.second)
{
// removing states
std::list<state*>::iterator i;
for (i = sscc.rem().begin(); i != sscc.rem().end(); ++i)
{
numbered_state_heap::state_index_p spi = h->index(
(*i)->clone());
assert(spi.first->compare(*i) == 0);
assert(*spi.second != -1);
*spi.second = -1;
}
dec_depth(sscc.rem().size());
sscc.pop();
}
for (i = sscc.rem().begin(); i != sscc.rem().end(); ++i)
{
numbered_state_heap::state_index_p spi = h->index(
(*i)->clone());
assert(spi.first->compare(*i) == 0);
assert(*spi.second != -1);
*spi.second = -1;
}
dec_depth(sscc.rem().size());
sscc.pop();
}
delete succ;
// Do not delete CURR: it is a key in H.
delete succ;
// Do not delete CURR: it is a key in H.
continue;
}
continue;
}
// We have a successor to look at.
inc_transitions();
trace
<< "PASS 2 : transition" << std::endl;
// Fetch the values destination state we are interested in...
state* dest = succ->current_state();
// We have a successor to look at.
inc_transitions();
trace
<< "PASS 2 : transition" << std::endl;
// Fetch the values destination state we are interested in...
state* dest = succ->current_state();
bool is_stuttering_transition = succ->is_stuttering_transition();
// ... and point the iterator to the next successor, for
// the next iteration.
succ->next();
// We do not need SUCC from now on.
bool is_stuttering_transition = succ->is_stuttering_transition();
// ... and point the iterator to the next successor, for
// the next iteration.
succ->next();
// We do not need SUCC from now on.
numbered_state_heap::state_index_p spi = h->find(dest);
numbered_state_heap::state_index_p spi = h->find(dest);
// Is this a new state?
if (!spi.first)
{
// Is this a new state?
if (!spi.first)
{
// Are we going to a new state through a stuttering transition?
// Are we going to a new state through a stuttering transition?
if (!is_stuttering_transition)
{
init_set.push(dest);
continue;
}
if (!is_stuttering_transition)
{
init_set.push(dest);
continue;
}
// Number it, stack it, and register its successors
// for later processing.
h->insert(dest, ++num);
sscc.push(num);
sscc.top().is_accepting = t->is_livelock_accepting_state(dest);
// Number it, stack it, and register its successors
// for later processing.
h->insert(dest, ++num);
sscc.push(num);
sscc.top().is_accepting = t->is_livelock_accepting_state(dest);
ta_succ_iterator* iter = t->succ_iter(dest);
iter->first();
todo.push(pair_state_iter(dest, iter));
inc_depth();
continue;
}
ta_succ_iterator* iter = t->succ_iter(dest);
iter->first();
todo.push(pair_state_iter(dest, iter));
inc_depth();
continue;
}
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
continue;
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
continue;
//self loop state
if (!curr->compare(spi.first))
{
state * self_loop_state = (curr);
//self loop state
if (!curr->compare(spi.first))
{
state * self_loop_state = (curr);
if (t->is_livelock_accepting_state(self_loop_state))
{
clear(h, todo, init_set);
trace
<< "PASS 2: SUCCESS" << std::endl;
return true;
}
if (t->is_livelock_accepting_state(self_loop_state))
{
clear(h, todo, init_set);
trace
<< "PASS 2: SUCCESS" << std::endl;
return true;
}
}
}
// Now this is the most interesting case. We have reached a
// state S1 which is already part of a non-dead SSCC. Any such
// non-dead SSCC has necessarily been crossed by our path to
// this state: there is a state S2 in our path which belongs
// to this SSCC too. We are going to merge all states between
// this S1 and S2 into this SSCC.
//
// This merge is easy to do because the order of the SSCC in
// ROOT is ascending: we just have to merge all SSCCs from the
// top of ROOT that have an index greater to the one of
// the SSCC of S2 (called the "threshold").
int threshold = *spi.second;
std::list<state*> rem;
bool acc = false;
// Now this is the most interesting case. We have reached a
// state S1 which is already part of a non-dead SSCC. Any such
// non-dead SSCC has necessarily been crossed by our path to
// this state: there is a state S2 in our path which belongs
// to this SSCC too. We are going to merge all states between
// this S1 and S2 into this SSCC.
//
// This merge is easy to do because the order of the SSCC in
// ROOT is ascending: we just have to merge all SSCCs from the
// top of ROOT that have an index greater to the one of
// the SSCC of S2 (called the "threshold").
int threshold = *spi.second;
std::list<state*> rem;
bool acc = false;
while (threshold < sscc.top().index)
{
assert(!sscc.empty());
while (threshold < sscc.top().index)
{
assert(!sscc.empty());
acc |= sscc.top().is_accepting;
acc |= sscc.top().is_accepting;
rem.splice(rem.end(), sscc.rem());
sscc.pop();
rem.splice(rem.end(), sscc.rem());
sscc.pop();
}
// Note that we do not always have
// threshold == sscc.top().index
// after this loop, the SSCC whose index is threshold might have
// been merged with a lower SSCC.
}
// Note that we do not always have
// threshold == sscc.top().index
// after this loop, the SSCC whose index is threshold might have
// been merged with a lower SSCC.
// Accumulate all acceptance conditions into the merged SSCC.
sscc.top().is_accepting |= acc;
// Accumulate all acceptance conditions into the merged SSCC.
sscc.top().is_accepting |= acc;
sscc.rem().splice(sscc.rem().end(), rem);
if (sscc.top().is_accepting)
{
clear(h, todo, init_set);
trace
<< "PASS 2: SUCCESS" << std::endl;
return true;
}
}
sscc.rem().splice(sscc.rem().end(), rem);
if (sscc.top().is_accepting)
{
clear(h, todo, init_set);
trace
<< "PASS 2: SUCCESS" << std::endl;
return true;
}
}
}
clear(h, todo, init_set);
@ -582,16 +593,16 @@ namespace spot
while (!init_states.empty())
{
a_->free_state(init_states.top());
init_states.pop();
a_->free_state(init_states.top());
init_states.pop();
}
// Release all iterators in TODO.
while (!todo.empty())
{
delete todo.top().second;
todo.pop();
dec_depth();
delete todo.top().second;
todo.pop();
dec_depth();
}
delete h;
}
@ -604,7 +615,7 @@ namespace spot
//TODO sscc;
os << scc.size() << " strongly connected components in search stack"
<< std::endl;
<< std::endl;
os << transitions() << " transitions explored" << std::endl;
os << max_depth() << " items max in DFS search stack" << std::endl;
return os;

8
src/taalgos/emptinessta.hh
View file

@ -24,7 +24,7 @@
#ifndef SPOT_TAALGOS_EMPTINESS_HH
# define SPOT_TAALGOS_EMPTINESS_HH
#include "ta/ta.hh"
#include "ta/taproduct.hh"
#include "misc/optionmap.hh"
#include "tgbaalgos/gtec/nsheap.hh"
#include "tgbaalgos/emptiness_stats.hh"
@ -43,13 +43,13 @@ namespace spot
class ta_check : public ec_statistics
{
public:
ta_check(const ta* a, option_map o = option_map());
ta_check(const ta_product* a, option_map o = option_map());
virtual
~ta_check();
/// Check whether the automaton's language is empty.
virtual bool
check();
check(bool disable_second_pass = false);
virtual bool
livelock_detection(const ta* t);
@ -75,7 +75,7 @@ namespace spot
heuristic_livelock_detection(const state * stuttering_succ,
numbered_state_heap* h, int h_livelock_root, std::set<const state*,
state_ptr_less_than> liveset_curr);
const ta* a_; ///< The automaton.
const ta_product* a_; ///< The automaton.
option_map o_; ///< The options
bool is_full_2_pass_;

47
src/taalgos/minimize.cc
View file

@ -106,7 +106,7 @@ namespace spot
state* tgba_state = tgba->add_state(src_num);
bdd tgba_condition = bddtrue;
bool is_initial_state = a->is_initial_state(src);
if (is_initial_state)
if ((a->get_artificial_initial_state() == 0) && is_initial_state)
tgba_condition = a->get_state_condition(src);
bool is_accepting_state = a->is_accepting_state(src);
bool is_livelock_accepting_state = a->is_livelock_accepting_state(src);
@ -120,10 +120,16 @@ namespace spot
if (ta_src != new_src)
{
new_src->destroy();
tgba_state->destroy();
}
else if (a->get_artificial_initial_state() != 0)
{
if (a->get_artificial_initial_state() == src)
ta->set_artificial_initial_state(new_src);
}
else if (is_initial_state)
ta->add_to_initial_states_set(new_src);
{
ta->add_to_initial_states_set(new_src);
}
ta_succ_iterator* succit = a->succ_iter(src);
@ -138,7 +144,7 @@ namespace spot
state* tgba_state = tgba->add_state(i->second);
bdd tgba_condition = bddtrue;
is_initial_state = a->is_initial_state(dst);
if (is_initial_state)
if ((a->get_artificial_initial_state() == 0) && is_initial_state)
tgba_condition = a->get_state_condition(dst);
bool is_accepting_state = a->is_accepting_state(dst);
bool is_livelock_accepting_state = a->is_livelock_accepting_state(
@ -153,8 +159,13 @@ namespace spot
if (ta_dst != new_dst)
{
new_dst->destroy();
tgba_state->destroy();
}
else if (a->get_artificial_initial_state() != 0)
{
if (a->get_artificial_initial_state() == dst)
ta->set_artificial_initial_state(new_dst);
}
else if (is_initial_state)
ta->add_to_initial_states_set(new_dst);
@ -196,11 +207,17 @@ namespace spot
std::set<const state*>::iterator it;
spot::state* artificial_initial_state = ta_->get_artificial_initial_state();
for (it = states_set.begin(); it != states_set.end(); it++)
{
const state* s = (*it);
if (ta_->is_initial_state(s))
if (s == artificial_initial_state)
{
I->insert(s);
}
else if (artificial_initial_state == 0 && ta_->is_initial_state(s))
{
I->insert(s);
}
@ -254,12 +271,13 @@ namespace spot
}
}
delete I;
if (!G->empty())
delete I;
if (!G->empty())
{
unsigned s = G->size();
unsigned num = ++set_num;
unsigned num = set_num;
set_num++;
used_var[num] = s;
free_var.erase(num);
if (s > 1)
@ -276,7 +294,8 @@ namespace spot
if (!F->empty())
{
unsigned s = F->size();
unsigned num = ++set_num;
unsigned num = set_num;
set_num++;
used_var[num] = s;
free_var.erase(num);
if (s > 1)
@ -292,7 +311,8 @@ namespace spot
if (!G_F->empty())
{
unsigned s = G_F->size();
unsigned num = ++set_num;
unsigned num = set_num;
set_num++;
used_var[num] = s;
free_var.erase(num);
if (s > 1)
@ -308,7 +328,8 @@ namespace spot
if (!S->empty())
{
unsigned s = S->size();
unsigned num = ++set_num;
unsigned num = set_num;
set_num++;
used_var[num] = s;
free_var.erase(num);
if (s > 1)

19
src/taalgos/reachiter.cc
View file

@ -51,10 +51,23 @@ namespace spot
{
int n = 0;
start();
const ta::states_set_t init_states_set =
t_automata_->get_initial_states_set();
spot::state* artificial_initial_state =
t_automata_->get_artificial_initial_state();
ta::states_set_t init_states_set;
ta::states_set_t::const_iterator it;
if (artificial_initial_state != 0)
{
init_states_set.insert(artificial_initial_state);
}
else
{
init_states_set = t_automata_->get_initial_states_set();
}
for (it = init_states_set.begin(); it != init_states_set.end(); it++)
{
state* init_state = (*it);
@ -89,7 +102,7 @@ namespace spot
{
if (ws)
process_link(tn, s->second, si);
t_automata_->free_state(current);
t_automata_->free_state(current);
}
}
delete si;

508
src/taalgos/sba2ta.cc
View file

@ -29,6 +29,7 @@
#include "tgbaalgos/gtec/nsheap.hh"
#include <stack>
#include "sba2ta.hh"
#include "taalgos/statessetbuilder.hh"
using namespace std;
@ -36,93 +37,193 @@ namespace spot
{
ta*
sba_to_ta(const tgba_sba_proxy* tgba_, bdd atomic_propositions_set_)
sba_to_ta(const tgba_sba_proxy* tgba_, bdd atomic_propositions_set_,
bool artificial_initial_state_mode,
bool artificial_livelock_accepting_state_mode)
{
ta_explicit* ta = new spot::ta_explicit(tgba_);
ta_explicit* ta;
std::stack<state_ta_explicit*> todo;
// build Initial states set:
state* tgba_init_state = tgba_->get_init_state();
if (artificial_initial_state_mode)
{
state_ta_explicit* ta_init_state = new state_ta_explicit(
tgba_init_state->clone(), bddtrue, true);
ta = new spot::ta_explicit(tgba_, ta_init_state);
}
else
{
ta = new spot::ta_explicit(tgba_);
}
bdd tgba_condition = tgba_->support_conditions(tgba_init_state);
bdd satone_tgba_condition;
while ((satone_tgba_condition = bdd_satoneset(tgba_condition,
atomic_propositions_set_, bddtrue)) != bddfalse)
atomic_propositions_set_, bddtrue)) != bddfalse)
{
tgba_condition -= satone_tgba_condition;
state_ta_explicit* init_state = new state_ta_explicit(
tgba_init_state->clone(), satone_tgba_condition, true,
tgba_->state_is_accepting(tgba_init_state));
state_ta_explicit* is = ta->add_state(init_state);
assert(is == init_state);
ta->add_to_initial_states_set(is);
todo.push(init_state);
tgba_condition -= satone_tgba_condition;
state_ta_explicit* init_state = new state_ta_explicit(
tgba_init_state->clone(), satone_tgba_condition, true,
tgba_->state_is_accepting(tgba_init_state));
state_ta_explicit* s = ta->add_state(init_state);
assert(s == init_state);
ta->add_to_initial_states_set(s);
todo.push(init_state);
}
tgba_init_state->destroy();
while (!todo.empty())
{
state_ta_explicit* source = todo.top();
todo.pop();
state_ta_explicit* source = todo.top();
todo.pop();
tgba_succ_iterator* tgba_succ_it = tgba_->succ_iter(
source->get_tgba_state());
for (tgba_succ_it->first(); !tgba_succ_it->done(); tgba_succ_it->next())
{
const state* tgba_state = tgba_succ_it->current_state();
bdd tgba_condition = tgba_succ_it->current_condition();
bdd satone_tgba_condition;
while ((satone_tgba_condition = bdd_satoneset(tgba_condition,
atomic_propositions_set_, bddtrue)) != bddfalse)
{
tgba_succ_iterator* tgba_succ_it = tgba_->succ_iter(
source->get_tgba_state());
for (tgba_succ_it->first(); !tgba_succ_it->done(); tgba_succ_it->next())
{
const state* tgba_state = tgba_succ_it->current_state();
bdd tgba_condition = tgba_succ_it->current_condition();
bdd satone_tgba_condition;
while ((satone_tgba_condition = bdd_satoneset(tgba_condition,
atomic_propositions_set_, bddtrue)) != bddfalse)
{
tgba_condition -= satone_tgba_condition;
tgba_condition -= satone_tgba_condition;
bdd all_props = bddtrue;
bdd dest_condition;
if (satone_tgba_condition == source->get_tgba_condition())
while ((dest_condition = bdd_satoneset(all_props,
atomic_propositions_set_, bddtrue)) != bddfalse)
{
all_props -= dest_condition;
state_ta_explicit* new_dest = new state_ta_explicit(
tgba_state->clone(), dest_condition, false,
tgba_->state_is_accepting(tgba_state));
bdd all_props = bddtrue;
bdd dest_condition;
if (satone_tgba_condition == source->get_tgba_condition())
while ((dest_condition = bdd_satoneset(all_props,
atomic_propositions_set_, bddtrue)) != bddfalse)
{
all_props -= dest_condition;
state_ta_explicit* new_dest = new state_ta_explicit(
tgba_state->clone(), dest_condition, false,
tgba_->state_is_accepting(tgba_state));
state_ta_explicit* dest = ta->add_state(new_dest);
state_ta_explicit* dest = ta->add_state(new_dest);
if (dest != new_dest)
{
// the state dest already exists in the testing automata
new_dest->get_tgba_state()->destroy();
delete new_dest;
}
else
{
todo.push(dest);
}
if (dest != new_dest)
{
// the state dest already exists in the testing automata
new_dest->get_tgba_state()->destroy();
delete new_dest;
}
else
{
todo.push(dest);
}
ta->create_transition(source, bdd_setxor(
source->get_tgba_condition(),
dest->get_tgba_condition()), dest);
}
ta->create_transition(source, bdd_setxor(
source->get_tgba_condition(),
dest->get_tgba_condition()), dest);
}
}
tgba_state->destroy();
}
delete tgba_succ_it;
}
tgba_state->destroy();
}
delete tgba_succ_it;
}
compute_livelock_acceptance_states(ta);
if (artificial_livelock_accepting_state_mode)
{
state_ta_explicit* artificial_livelock_accepting_state =
new state_ta_explicit(ta->get_tgba()->get_init_state(), bddfalse,
false, false, true, 0, true);
state_ta_explicit* artificial_livelock_accepting_state_added = ta->add_state(artificial_livelock_accepting_state);
// unique artificial_livelock_accepting_state
assert(artificial_livelock_accepting_state_added
== artificial_livelock_accepting_state);
add_artificial_livelock_accepting_state(ta,
artificial_livelock_accepting_state_added);
}
return ta;
}
void
add_artificial_livelock_accepting_state(ta_explicit* testing_automata,
state_ta_explicit* artificial_livelock_accepting_state)
{
ta::states_set_t states_set = testing_automata->get_states_set();
ta::states_set_t::iterator it;
std::set<bdd, bdd_less_than>* conditions_to_livelock_accepting_states =
new std::set<bdd, bdd_less_than>;
for (it = states_set.begin(); it != states_set.end(); it++)
{
state_ta_explicit* source = static_cast<state_ta_explicit*> (*it);
conditions_to_livelock_accepting_states->clear();
state_ta_explicit::transitions* trans = source->get_transitions();
state_ta_explicit::transitions::iterator it_trans;
if (trans != 0)
for (it_trans = trans->begin(); it_trans != trans->end();)
{
state_ta_explicit* dest = (*it_trans)->dest;
if (dest->is_livelock_accepting_state())
{
conditions_to_livelock_accepting_states->insert(
(*it_trans)->condition);
}
//remove hole successors states
state_ta_explicit::transitions* dest_trans =
(dest)->get_transitions();
bool dest_trans_empty = dest_trans == 0 || dest_trans->empty();
if (dest_trans_empty)
{
source->get_transitions((*it_trans)->condition)->remove(
*it_trans);
delete (*it_trans);
it_trans = trans->erase(it_trans);
}
else
{
it_trans++;
}
}
if (conditions_to_livelock_accepting_states != 0)
{
std::set<bdd, bdd_less_than>::iterator it_conditions;
for (it_conditions
= conditions_to_livelock_accepting_states->begin(); it_conditions
!= conditions_to_livelock_accepting_states->end(); it_conditions++)
{
testing_automata->create_transition(source, (*it_conditions),
artificial_livelock_accepting_state);
}
}
}
delete conditions_to_livelock_accepting_states;
}
namespace
{
typedef std::pair<spot::state*, tgba_succ_iterator*> pair_state_iter;
@ -138,7 +239,7 @@ namespace spot
// * h: a hash of all visited nodes, with their order,
// (it is called "Hash" in Couvreur's paper)
numbered_state_heap* h =
numbered_state_heap_hash_map_factory::instance()->build(); ///< Heap of visited states.
numbered_state_heap_hash_map_factory::instance()->build(); ///< Heap of visited states.
// * num: the number of visited nodes. Used to set the order of each
// visited node,
@ -158,201 +259,200 @@ namespace spot
ta::states_set_t init_states = testing_automata->get_initial_states_set();
for (it = init_states.begin(); it != init_states.end(); it++)
{
state* init_state = down_cast<state_ta_explicit*> (*it);
init_set.push(init_state);
state* init_state = (*it);
init_set.push(init_state);
}
while (!init_set.empty())
{
// Setup depth-first search from initial states.
{
state_ta_explicit* init =
down_cast<state_ta_explicit*> (init_set.top());
init_set.pop();
state_ta_explicit* init_clone = init->clone();
numbered_state_heap::state_index_p h_init = h->find(init_clone);
// Setup depth-first search from initial states.
{
state_ta_explicit* init =
down_cast<state_ta_explicit*> (init_set.top());
init_set.pop();
state_ta_explicit* init_clone = init->clone();
numbered_state_heap::state_index_p h_init = h->find(init_clone);
if (h_init.first)
continue;
if (h_init.first)
continue;
h->insert(init_clone, ++num);
sscc.push(num);
sscc.top().is_accepting
= testing_automata->is_accepting_state(init);
tgba_succ_iterator* iter = testing_automata->succ_iter(init);
iter->first();
todo.push(pair_state_iter(init, iter));
h->insert(init_clone, ++num);
sscc.push(num);
sscc.top().is_accepting
= testing_automata->is_accepting_state(init);
tgba_succ_iterator* iter = testing_automata->succ_iter(init);
iter->first();
todo.push(pair_state_iter(init, iter));
}
}
while (!todo.empty())
{
while (!todo.empty())
{
state* curr = todo.top().first;
state* curr = todo.top().first;
numbered_state_heap::state_index_p spi = h->find(curr->clone());
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
{
todo.pop();
continue;
}
numbered_state_heap::state_index_p spi = h->find(curr->clone());
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
{
todo.pop();
continue;
}
// We are looking at the next successor in SUCC.
tgba_succ_iterator* succ = todo.top().second;
// We are looking at the next successor in SUCC.
tgba_succ_iterator* succ = todo.top().second;
// If there is no more successor, backtrack.
if (succ->done())
{
// We have explored all successors of state CURR.
// If there is no more successor, backtrack.
if (succ->done())
{
// We have explored all successors of state CURR.
// Backtrack TODO.
todo.pop();
// Backtrack TODO.
todo.pop();
// fill rem with any component removed,
numbered_state_heap::state_index_p spi =
h->index(curr->clone());
assert(spi.first);
// fill rem with any component removed,
numbered_state_heap::state_index_p spi =
h->index(curr->clone());
assert(spi.first);
sscc.rem().push_front(curr);
sscc.rem().push_front(curr);
// When backtracking the root of an SSCC, we must also
// remove that SSCC from the ROOT stacks. We must
// discard from H all reachable states from this SSCC.
assert(!sscc.empty());
if (sscc.top().index == *spi.second)
{
// removing states
std::list<state*>::iterator i;
bool is_livelock_accepting_sscc = (sscc.top().is_accepting
&& (sscc.rem().size() > 1));
for (i = sscc.rem().begin(); i != sscc.rem().end(); ++i)
{
numbered_state_heap::state_index_p spi = h->index(
(*i)->clone());
assert(spi.first->compare(*i) == 0);
assert(*spi.second != -1);
*spi.second = -1;
if (is_livelock_accepting_sscc)
{//if it is an accepting sscc
//add the state to G (=the livelock-accepting states set)
// When backtracking the root of an SSCC, we must also
// remove that SSCC from the ROOT stacks. We must
// discard from H all reachable states from this SSCC.
assert(!sscc.empty());
if (sscc.top().index == *spi.second)
{
// removing states
std::list<state*>::iterator i;
bool is_livelock_accepting_sscc = (sscc.top().is_accepting
&& (sscc.rem().size() > 1));
for (i = sscc.rem().begin(); i != sscc.rem().end(); ++i)
{
numbered_state_heap::state_index_p spi = h->index(
(*i)->clone());
assert(spi.first->compare(*i) == 0);
assert(*spi.second != -1);
*spi.second = -1;
if (is_livelock_accepting_sscc)
{//if it is an accepting sscc
//add the state to G (=the livelock-accepting states set)
state_ta_explicit * livelock_accepting_state =
down_cast<state_ta_explicit*> (*i);
state_ta_explicit * livelock_accepting_state =
down_cast<state_ta_explicit*> (*i);
livelock_accepting_state->set_livelock_accepting_state(
true);
livelock_accepting_state->set_livelock_accepting_state(
true);
}
}
}
}
sscc.pop();
sscc.pop();
}
}
// automata reduction
testing_automata->delete_stuttering_and_hole_successors(curr);
// automata reduction
testing_automata->delete_stuttering_and_hole_successors(curr);
delete succ;
// Do not delete CURR: it is a key in H.
continue;
}
delete succ;
// Do not delete CURR: it is a key in H.
continue;
}
// Fetch the values destination state we are interested in...
state* dest = succ->current_state();
// Fetch the values destination state we are interested in...
state* dest = succ->current_state();
// ... and point the iterator to the next successor, for
// the next iteration.
succ->next();
// We do not need SUCC from now on.
// ... and point the iterator to the next successor, for
// the next iteration.
succ->next();
// We do not need SUCC from now on.
// Are we going to a new state through a stuttering transition?
bool is_stuttering_transition =
testing_automata->get_state_condition(curr)
== testing_automata->get_state_condition(dest);
state* dest_clone = dest->clone();
spi = h->find(dest_clone);
// Are we going to a new state through a stuttering transition?
bool is_stuttering_transition =
testing_automata->get_state_condition(curr)
== testing_automata->get_state_condition(dest);
state* dest_clone = dest->clone();
spi = h->find(dest_clone);
// Is this a new state?
if (!spi.first)
{
if (!is_stuttering_transition)
{
init_set.push(dest);
dest_clone->destroy();
continue;
}
// Is this a new state?
if (!spi.first)
{
if (!is_stuttering_transition)
{
init_set.push(dest);
dest_clone->destroy();
continue;
}
// Number it, stack it, and register its successors
// for later processing.
h->insert(dest_clone, ++num);
sscc.push(num);
sscc.top().is_accepting = testing_automata->is_accepting_state(
dest);
// Number it, stack it, and register its successors
// for later processing.
h->insert(dest_clone, ++num);
sscc.push(num);
sscc.top().is_accepting = testing_automata->is_accepting_state(
dest);
tgba_succ_iterator* iter = testing_automata->succ_iter(dest);
iter->first();
todo.push(pair_state_iter(dest, iter));
continue;
}
tgba_succ_iterator* iter = testing_automata->succ_iter(dest);
iter->first();
todo.push(pair_state_iter(dest, iter));
continue;
}
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
continue;
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
continue;
if (!curr->compare(dest))
{
state_ta_explicit * self_loop_state =
down_cast<state_ta_explicit*> (curr);
assert(self_loop_state);
if (!curr->compare(dest))
{
state_ta_explicit * self_loop_state =
down_cast<state_ta_explicit*> (curr);
assert(self_loop_state);
if (testing_automata->is_accepting_state(self_loop_state))
self_loop_state->set_livelock_accepting_state(true);
if (testing_automata->is_accepting_state(self_loop_state))
self_loop_state->set_livelock_accepting_state(true);
}
}
// Now this is the most interesting case. We have reached a
// state S1 which is already part of a non-dead SSCC. Any such
// non-dead SSCC has necessarily been crossed by our path to
// this state: there is a state S2 in our path which belongs
// to this SSCC too. We are going to merge all states between
// this S1 and S2 into this SSCC.
//
// This merge is easy to do because the order of the SSCC in
// ROOT is ascending: we just have to merge all SSCCs from the
// top of ROOT that have an index greater to the one of
// the SSCC of S2 (called the "threshold").
int threshold = *spi.second;
std::list<state*> rem;
bool acc = false;
// Now this is the most interesting case. We have reached a
// state S1 which is already part of a non-dead SSCC. Any such
// non-dead SSCC has necessarily been crossed by our path to
// this state: there is a state S2 in our path which belongs
// to this SSCC too. We are going to merge all states between
// this S1 and S2 into this SSCC.
//
// This merge is easy to do because the order of the SSCC in
// ROOT is ascending: we just have to merge all SSCCs from the
// top of ROOT that have an index greater to the one of
// the SSCC of S2 (called the "threshold").
int threshold = *spi.second;
std::list<state*> rem;
bool acc = false;
while (threshold < sscc.top().index)
{
assert(!sscc.empty());
while (threshold < sscc.top().index)
{
assert(!sscc.empty());
acc |= sscc.top().is_accepting;
acc |= sscc.top().is_accepting;
rem.splice(rem.end(), sscc.rem());
sscc.pop();
rem.splice(rem.end(), sscc.rem());
sscc.pop();
}
// Note that we do not always have
// threshold == sscc.top().index
// after this loop, the SSCC whose index is threshold might have
// been merged with a lower SSCC.
}
// Note that we do not always have
// threshold == sscc.top().index
// after this loop, the SSCC whose index is threshold might have
// been merged with a lower SSCC.
// Accumulate all acceptance conditions into the merged SSCC.
sscc.top().is_accepting |= acc;
// Accumulate all acceptance conditions into the merged SSCC.
sscc.top().is_accepting |= acc;
sscc.rem().splice(sscc.rem().end(), rem);
sscc.rem().splice(sscc.rem().end(), rem);
}
}
}
delete h;
}
}

11
src/taalgos/sba2ta.hh
View file

@ -31,13 +31,18 @@
#include "misc/bddlt.hh"
#include "ta/taexplicit.hh"
namespace spot
{
ta* sba_to_ta(const tgba_sba_proxy* tgba_to_convert, bdd atomic_propositions_set);
ta*
sba_to_ta(const tgba_sba_proxy* tgba_to_convert, bdd atomic_propositions_set, bool artificial_initial_state_mode = true,
bool artificial_livelock_accepting_state_mode = false);
void
compute_livelock_acceptance_states(ta_explicit* testing_automata);
void compute_livelock_acceptance_states(ta_explicit* testing_automata);
void
add_artificial_livelock_accepting_state(ta_explicit* testing_automata,
state_ta_explicit* artificial_livelock_accepting_state);
}