Commit 78e76eb0 authored by Alexandre Duret-Lutz's avatar Alexandre Duret-Lutz

dbacomp: connect only back-links and generalize to tgba

* src/tgbaalgos/dbacomp.cc: Here.
* src/tgbaalgos/dbacomp.hh: Adjust documentation.
* src/tgbatest/dbacomp.test: New file.
* src/tgbatest/Makefile.am (TESTS): Add it.
* src/tgbatest/det.test: Update.
parent 63b7cdb6
......@@ -26,37 +26,32 @@ namespace spot
namespace
{
class dbacomp_iter: public tgba_reachable_iterator_depth_first
class dbacomp_iter: public tgba_reachable_iterator_depth_first_stack
{
bdd orig_acc_;
bdd all_neg_;
bdd acc_;
bdd_dict* dict_;
tgba_explicit_number* out_;
int num_acc_;
typedef state_explicit_number::transition trans;
public:
dbacomp_iter(const tgba* a)
: tgba_reachable_iterator_depth_first(a),
: tgba_reachable_iterator_depth_first_stack(a),
dict_(a->get_dict()),
out_(new tgba_explicit_number(dict_))
{
dict_->register_all_variables_of(a, out_);
unsigned c = a->number_of_acceptance_conditions();
orig_acc_ = a->all_acceptance_conditions();
if (c == 1)
{
out_->copy_acceptance_conditions_of(a);
acc_ = orig_acc_;
}
else
{
// If there is no acceptance conditions in the original
// automaton, add one.
assert(c == 0);
int accvar = dict_->register_acceptance_variable
(ltl::constant::true_instance(), out_);
acc_ = bdd_ithvar(accvar);
out_->set_acceptance_conditions(acc_);
}
all_neg_ = a->neg_acceptance_conditions();
num_acc_ = a->number_of_acceptance_conditions();
// Register one acceptance condition for the result.
int accvar = dict_->register_acceptance_variable
(ltl::constant::true_instance(), out_);
acc_ = bdd_ithvar(accvar);
out_->set_acceptance_conditions(acc_);
}
tgba_explicit_number*
......@@ -106,19 +101,61 @@ namespace spot
trans* t1 = out_->create_transition(in, out);
t1->condition = si->current_condition();
// Negative states encode a copy of the automaton in which all
// accepting transitions have been removed, and all the
// remaining transitions are now accepting.
// Negative states encode NUM_ACC_ copies of the automaton.
// In each copy transitions labeled by one of the acceptance
// set have been removed, and all the remaining transitions
// are now accepting.
// For each state S, we have NUM_ACC_ additional copies
// labeled S*-NUM_ACC, S*-NUM_ACC+1, ... S*-NUM_ACC+(NUM_ACC-1),
if (a != orig_acc_)
{
trans* t2 = out_->create_transition(-in, -out);
t2->condition = si->current_condition();
t2->acceptance_conditions = acc_;
}
bool backlink = on_stack(out);
int add = 0;
if (a == bddfalse)
a = all_neg_;
// Iterate over all the acceptance conditions in 'a'.
bdd ac = a;
while (ac != bddtrue)
{
bdd h = bdd_high(ac);
if (h == bddfalse)
{
trans* t2 = out_->create_transition(in * -num_acc_ + add,
out * -num_acc_ + add);
t2->condition = si->current_condition();
t2->acceptance_conditions = acc_;
// A non-deterministic transition between the two copies.
trans* t3 = out_->create_transition(in, -out);
t3->condition = si->current_condition();
if (backlink)
{
// Since we are closing a cycle, add
// a non-deterministic transition from
// the original automaton to this copy.
trans* t3 =
out_->create_transition(in, out * -num_acc_ + add);
t3->condition = si->current_condition();
}
ac = bdd_low(ac);
}
else
{
// We know that only one variable can be positive
// on any branch, so since we have just seen such
// a variable, we want to go to explore its LOW
// branch for more positive variables. The only
// case where we will not do that is if the LOW
// branch is false. In that case we take the HIGH
// branch to enumerate all the remaining negated
// variables.
bdd tmp = bdd_low(ac);
if (tmp != bddfalse)
ac = tmp;
else
ac = h;
}
++add;
}
assert(add == num_acc_);
}
}
};
......
......@@ -24,13 +24,11 @@
namespace spot
{
/// Complement a deterministic Büchi automaton
/// \brief Complement a deterministic Büchi automaton
///
/// The automaton \a aut should be deterministic and should have at
/// most a single acceptance condition. It can be transition-based,
/// or state-based. The resulting automaton is very unlikely to be
/// The automaton \a aut should be deterministic. It does no need
/// to be complete. Acceptance can be transition-based, or
/// state-based. The resulting automaton is very unlikely to be
/// deterministic.
SPOT_API tgba_explicit_number*
dba_complement(const tgba* aut);
......
......@@ -107,6 +107,7 @@ TESTS = \
lbttparse.test \
scc.test \
sccsimpl.test \
dbacomp.test \
obligation.test \
wdba.test \
wdba2.test \
......
#!/bin/sh
# -*- coding: utf-8 -*-
# Copyright (C) 2013 Laboratoire de Recherche et
# Développement de l'Epita (LRDE).
#
# This file is part of Spot, a model checking library.
#
# Spot is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# Spot is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
# License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
. ./defs
# This automaton used to trigger a bug in the complementation: its
# intersection with the complement was not empty!
cat >input.tgba <<EOF
acc = "a" "b" "c";
"1", "1", "(a & d) | (a & b)", "b" "c";
"1", "2", "a & !d & !c & !b",;
"1", "1", "(d & !a) | (b & !a)", "a" "b" "c";
"1", "2", "!a & !d & !c & !b", "a";
"2", "1", "a & c & b", "b" "c";
"2", "3", "a & b & !c", "b";
"2", "2", "a & !c & !b",;
"2", "1", "c & b & !a", "a" "b" "c";
"2", "3", "b & !a & !c", "a" "b";
"2", "2", "!a & !c & !b", "a";
"3", "1", "(a & d & c) | (a & c & b)", "b" "c";
"3", "3", "(a & d & !c) | (a & b & !c)", "b";
"3", "2", "a & !d & !c & !b",;
"3", "1", "(d & c & !a) | (c & b & !a)", "a" "b" "c";
"3", "3", "(d & !a & !c) | (b & !a & !c)", "a" "b";
"3", "2", "!a & !d & !c & !b", "a";
EOF
# Check emptiness of product with complement.
run 0 ../ltl2tgba -Pinput.tgba -DC -E -C -X input.tgba
......@@ -69,6 +69,7 @@ acc = "1";
"3", "1", "!a",;
EOF
# FIXME: we should improve this output
cat >ex.tgba <<'EOF'
acc = "1";
"1", "2", "a",;
......@@ -76,13 +77,35 @@ acc = "1";
"1", "-1", "!a",;
"2", "3", "a",;
"2", "1", "!a",;
"2", "-1", "!a",;
"-1", "-1", "!a", "1";
"3", "3", "a",;
"3", "-3", "a",;
"3", "1", "!a",;
"3", "-1", "!a",;
"-3", "-3", "a", "1";
"-3", "-1", "!a", "1";
EOF
run 0 ../ltl2tgba -b -DC -X in.tgba > out.tgba
cmp out.tgba ex.tgba
diff out.tgba ex.tgba
run 0 ../ltl2tgba -x -DC 'GFa & XGFb' > out.tgba
cat >ex.tgba <<EOF
digraph G {
0 [label="", style=invis, height=0]
0 -> 1
1 [label="1"]
1 -> 2 [label="1\n"]
2 [label="2"]
2 -> 2 [label="1\n"]
2 -> 3 [label="!a\n"]
2 -> 4 [label="!b\n"]
3 [label="-4"]
3 -> 3 [label="!a\n{Acc[1]}"]
4 [label="-3"]
4 -> 4 [label="!b\n{Acc[1]}"]
}
EOF
diff out.tgba ex.tgba
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