alarsyo/spot
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Inf(i)|Inf(j) -> Inf(k) and Fin(i)&Fin(j) -> Fin(k)

Browse source 
Implement those rules in simplify_acceptance_here().

* NEWS: Mention the change.
* spot/twa/acc.cc,
spot/twa/acc.hh (acc_cond::acc_code::used_once_sets): New method.
* spot/twaalgos/cleanacc.cc, spot/twaalgos/cleanacc.hh:
Implement the above rule.
* tests/core/remfin.test: Adjust expected results.
* tests/python/simplacc.py: New file.
* tests/Makefile.am: Add it.
This commit is contained in:
Alexandre Duret-Lutz 2020-01-27 22:50:17 +01:00
parent 5dc6da0b20
commit 50c0f880dc
8 changed files with 416 additions and 23 deletions
Download patch file Download diff file Expand all files Collapse all files

7
NEWS
View file

@ -61,6 +61,13 @@ New in spot 2.8.5.dev (not yet released)
degeneralization to get rid of conjunction of Inf terms in
acceptance conditions.
- simplify_acceptance_here() and simplify_acceptance() learned to
simplify subformulas like Fin(i)&Fin(j) or Inf(i)|Inf(j), or some
more complex variants of those. If i us uniquely used in the
acceptance condition these become respectively Fin(i) or Inf(i),
and the automaton is adjusted to that i also appears where j
appeared.
New in spot 2.8.5 (2020-01-04)
Bugs fixed:

33
spot/twa/acc.cc
View file

@ -1,5 +1,5 @@
// -*- coding: utf-8 -*-
// Copyright (C) 2015-2019 Laboratoire de Recherche et Développement
// Copyright (C) 2015-2020 Laboratoire de Recherche et Développement
// de l'Epita.
//
// This file is part of Spot, a model checking library.
@ -2340,6 +2340,7 @@ namespace spot
std::swap(c, *this);
}
int acc_cond::acc_code::fin_one() const
{
if (empty() || is_f())
@ -2398,4 +2399,34 @@ namespace spot
while (pos >= &front());
return res;
}
acc_cond::mark_t acc_cond::acc_code::used_once_sets() const
{
mark_t seen = {};
mark_t dups = {};
if (empty())
return {};
const acc_cond::acc_word* pos = &back();
do
{
switch (pos->sub.op)
{
case acc_cond::acc_op::And:
case acc_cond::acc_op::Or:
--pos;
break;
case acc_cond::acc_op::Inf:
case acc_cond::acc_op::InfNeg:
case acc_cond::acc_op::FinNeg:
case acc_cond::acc_op::Fin:
auto m = pos[-1].mark;
pos -= 2;
dups |= m & seen;
seen |= m;
break;
}
}
while (pos >= &front());
return seen - dups;
}
}

12
spot/twa/acc.hh
View file

@ -1,5 +1,5 @@
// -*- coding: utf-8 -*-
// Copyright (C) 2014-2019 Laboratoire de Recherche et Développement
// Copyright (C) 2014-2020 Laboratoire de Recherche et Développement
// de l'Epita.
//
// This file is part of Spot, a model checking library.
@ -1199,7 +1199,7 @@ namespace spot
///
/// If multiple unit-Fin appear as unit-clauses, the set of
/// those will be returned. For instance applied to
/// `Fin(0)&Fin(1)&(Inf(2)|Fin(3))``, this will return `{0,1}`.
/// `Fin(0)&Fin(1)&(Inf(2)|Fin(3))`, this will return `{0,1}`.
mark_t fin_unit() const;
/// \brief Return one acceptance set i that appear as `Fin(i)`
@ -1286,6 +1286,14 @@ namespace spot
/// \brief Return the set of sets appearing in the condition.
acc_cond::mark_t used_sets() const;
/// \brief Return the sets that appears only once in the
/// acceptance.
///
/// For instance if the condition is
/// `Fin(0)&(Inf(1)|(Fin(1)&Inf(2)))`, this returns `{0,2}`,
/// because set `1` is used more than once.
mark_t used_once_sets() const;
/// \brief Return the sets used as Inf or Fin in the acceptance condition
std::pair<acc_cond::mark_t, acc_cond::mark_t> used_inf_fin_sets() const;

292
spot/twaalgos/cleanacc.cc
View file

@ -1,5 +1,5 @@
// -*- coding: utf-8 -*-
// Copyright (C) 2015, 2017-2019 Laboratoire de Recherche et Développement
// Copyright (C) 2015, 2017-2020 Laboratoire de Recherche et Développement
// de l'Epita.
//
// This file is part of Spot, a model checking library.
@ -320,6 +320,292 @@ namespace spot
complement));
return aut;
}
acc_cond::acc_code acc_rewrite_rec(const acc_cond::acc_word* pos)
{
auto start = pos - pos->sub.size;
switch (pos->sub.op)
{
case acc_cond::acc_op::And:
{
--pos;
auto res = acc_cond::acc_code::t();
do
{
auto tmp = acc_rewrite_rec(pos);
tmp &= std::move(res);
std::swap(tmp, res);
pos -= pos->sub.size + 1;
}
while (pos > start);
return res;
}
case acc_cond::acc_op::Or:
{
--pos;
auto res = acc_cond::acc_code::f();
do
{
auto tmp = acc_rewrite_rec(pos);
tmp |= std::move(res);
std::swap(tmp, res);
pos -= pos->sub.size + 1;
}
while (pos > start);
return res;
}
case acc_cond::acc_op::Fin:
return acc_cond::acc_code::fin(pos[-1].mark);
case acc_cond::acc_op::Inf:
return acc_cond::acc_code::inf(pos[-1].mark);
case acc_cond::acc_op::FinNeg:
case acc_cond::acc_op::InfNeg:
SPOT_UNREACHABLE();
};
SPOT_UNREACHABLE();
return {};
}
acc_cond::mark_t find_interm_rec(acc_cond::acc_word* pos)
{
acc_cond::acc_op wanted;
auto topop = pos->sub.op;
if (topop == acc_cond::acc_op::Or)
{
wanted = acc_cond::acc_op::Fin;
}
else
{
wanted = acc_cond::acc_op::Inf;
assert(topop == acc_cond::acc_op::And);
}
acc_cond::mark_t res = {};
const acc_cond::acc_word* rend = pos - (pos->sub.size + 1);
--pos;
do
switch (auto op = pos->sub.op)
{
case acc_cond::acc_op::Inf:
case acc_cond::acc_op::Fin:
case acc_cond::acc_op::InfNeg:
case acc_cond::acc_op::FinNeg:
{
auto m = pos[-1].mark;
if (op == wanted && m == m.lowest())
{
res |= m;
}
else
{
return {};
}
pos -= 2;
break;
}
case acc_cond::acc_op::And:
case acc_cond::acc_op::Or:
if (op == topop)
{
if (auto m = find_interm_rec(pos))
res |= m;
else
return {};
pos -= pos->sub.size + 1;
}
else
{
auto posend = pos - (pos->sub.size + 1);
--pos;
bool seen = false;
do
{
switch (auto op = pos->sub.op)
{
case acc_cond::acc_op::Inf:
case acc_cond::acc_op::Fin:
case acc_cond::acc_op::InfNeg:
case acc_cond::acc_op::FinNeg:
if (op == wanted)
{
auto m = pos[-1].mark;
if (!seen && m == m.lowest())
{
seen = true;
res |= m;
}
else
{
return {};
}
}
pos -= 2;
break;
case acc_cond::acc_op::And:
case acc_cond::acc_op::Or:
return {};
}
}
while (pos > posend);
}
break;
}
while (pos > rend);
return res;
}
// Replace Inf(i)|Inf(j) by Inf(k)
// or Fin(i)&Fin(j) by Fin(k)
// For this to work, k must be one of i or j,
// k must be used only once in the acceptance
// the transitions have to be updated: every transition marked
// by i or j should be marked by k.
void fuse_marks_here(twa_graph_ptr aut)
{
acc_cond::acc_code acccopy = aut->get_acceptance();
acc_cond::mark_t once = acccopy.used_once_sets();
if (!once)
return;
acc_cond::acc_word* pos = &acccopy.back();
const acc_cond::acc_word* front = &acccopy.front();
// a list of pairs ({i}, {j, k, l, ...}) where i is a set
// occurring once that can be removed if all transitions in set
// i are added to sets j,k,l, ...
std::vector<std::pair<acc_cond::mark_t, acc_cond::mark_t>> to_fuse;
auto find_fusable = [&](acc_cond::acc_word* pos)
{
acc_cond::acc_op wanted;
auto topop = pos->sub.op;
if (topop == acc_cond::acc_op::And)
{
wanted = acc_cond::acc_op::Fin;
}
else
{
wanted = acc_cond::acc_op::Inf;
assert(topop == acc_cond::acc_op::Or);
}
// Return a vector of "singleton-sets" of
// the wanted type in the operand of the
// pointed Or/And operator. For instance,
// assuming wanted=Inf and pos points to
//
// Inf({1})|Inf({2,3})|Fin({4})
// |Inf({5})|Inf({5})|Inf({6})
//
// This returns [({1}, Inf({1})),
// ({5}, Inf({5}))]].
std::vector<std::pair<acc_cond::mark_t,
acc_cond::acc_word*>>
singletons;
const acc_cond::acc_word* rend =
pos - (pos->sub.size + 1);
--pos;
do
{
switch (auto op = pos->sub.op)
{
case acc_cond::acc_op::InfNeg:
case acc_cond::acc_op::FinNeg:
case acc_cond::acc_op::Inf:
case acc_cond::acc_op::Fin:
{
auto m = pos[-1].mark;
if (op == wanted && m == m.lowest())
singletons.emplace_back(m, pos);
pos -= 2;
}
break;
case acc_cond::acc_op::And:
case acc_cond::acc_op::Or:
// On
// Fin(a)&(Fin(b)&Inf(c)|Fin(d))
// where we'd like to return [{a},
// {b,d}] and decide later that
// {b,d} can receive {a} if they
// (b and d) are both used once.
if (auto m = find_interm_rec(pos))
{
singletons.emplace_back(m, pos);
// move this to the front, to
// be sure it is the first
// recipient tried.
swap(singletons.front(),
singletons.back());
}
pos -= pos->sub.size + 1;
break;
}
}
while (pos > rend);
acc_cond::mark_t can_receive = {};
for (auto p: singletons)
if ((p.first & once) == p.first)
{
can_receive = p.first;
break;
}
if (!can_receive)
return;
for (auto p: singletons)
if (p.first != can_receive)
{
to_fuse.emplace_back(p.first, can_receive);
if (p.second->sub.op == acc_cond::acc_op::Fin)
p.second->sub.op = acc_cond::acc_op::Inf;
else
p.second->sub.op = acc_cond::acc_op::Fin;
p.second[-1].mark = {};
}
};
do
{
switch (pos->sub.op)
{
case acc_cond::acc_op::And:
case acc_cond::acc_op::Or:
find_fusable(pos);
// Don't skip to entire operands, as we might find
// fusable sub-parts.
--pos;
break;
case acc_cond::acc_op::Inf:
case acc_cond::acc_op::InfNeg:
case acc_cond::acc_op::FinNeg:
case acc_cond::acc_op::Fin:
pos -= 2;
break;
}
}
while (pos >= front);
if (to_fuse.empty())
return;
// Update the transition according to to_fuse.
for (auto pair: to_fuse)
if (pair.first & once) // can we remove pair.first?
{
for (auto& e: aut->edges())
if (e.acc & pair.first)
e.acc = (e.acc - pair.first) | pair.second;
}
else
{
for (auto& e: aut->edges())
if (e.acc & pair.first)
e.acc |= pair.second;
}
// Now rewrite the acceptance condition, removing all the "to_kill" terms.
aut->set_acceptance(aut->num_sets(), acc_rewrite_rec(&acccopy.back()));
}
}
twa_graph_ptr simplify_acceptance_here(twa_graph_ptr aut)
@ -327,9 +613,11 @@ namespace spot
cleanup_acceptance_here(aut, false);
merge_identical_marks_here(aut);
if (!aut->acc().is_generalized_buchi())
{
simplify_complementary_marks_here(aut);
fuse_marks_here(aut);
}
cleanup_acceptance_here(aut, true);
return aut;
}

7
spot/twaalgos/cleanacc.hh
View file

@ -1,5 +1,5 @@
// -*- coding: utf-8 -*-
// Copyright (C) 2015, 2017-2019 Laboratoire de Recherche et
// Copyright (C) 2015, 2017-2020 Laboratoire de Recherche et
// Développement de l'Epita.
//
// This file is part of Spot, a model checking library.
@ -57,6 +57,11 @@ namespace spot
/// - `Fin(i) | Inf(j) = Inf(j)`
/// - `Inf(i) | Inf(j) = t`
/// - `Fin(i) | Inf(i) = t`
/// And also merge terms like `Inf(i)|Inf(j)` or `Fin(i)&Fin(j)`
/// provided at least i or j is used uniquely in the formula.
/// (for instance if i is unique, `Inf(i)|Inf(j)` is rewritten
/// as `Inf(i)`, and `i` is added on all transitions where `j` is present
/// in the automaton.)
///
/// simplify_acceptance_here() works in place, simplify_acceptance()
/// returns a new automaton that has been simplified.

4
tests/Makefile.am
View file

@ -1,6 +1,5 @@
## -*- coding: utf-8 -*-
## Copyright (C) 2009-2019 Laboratoire de Recherche et Développement
## Copyright (C) 2009-2020 Laboratoire de Recherche et Développement
## de l'Epita (LRDE).
## Copyright (C) 2003-2006 Laboratoire d'Informatique de Paris 6
## (LIP6), département Systèmes Répartis Coopératifs (SRC), Université
@ -410,6 +409,7 @@ TESTS_python = \
python/semidet.py \
python/setacc.py \
python/setxor.py \
python/simplacc.py \
python/simstate.py \
python/split.py \
python/streett_totgba.py \

28
tests/core/remfin.test
View file

@ -1,8 +1,7 @@
#!/bin/sh
# -*- coding: utf-8 -*-
# Copyright (C) 2015-2018 Laboratoire de Recherche et Développement de
# l'Epita (LRDE).
# Copyright (C) 2015-2018, 2020 Laboratoire de Recherche et
# Développement de l'Epita (LRDE).
#
# This file is part of Spot, a model checking library.
#
@ -340,7 +339,7 @@ HOA: v1
States: 4
Start: 0
AP: 2 "a" "b"
Acceptance: 5 (Inf(0)&Inf(1)&Inf(4)) | Inf(0) | (Inf(2)&Inf(3))
Acceptance: 4 (Inf(0)&Inf(1)) | Inf(0) | (Inf(2)&Inf(3))
properties: trans-labels explicit-labels trans-acc
--BODY--
State: 0
@ -357,7 +356,7 @@ State: 2
[!0&!1] 2 {0}
[!0&!1] 3
State: 3
[!0&!1] 3 {0 1 4}
[!0&!1] 3 {0 1}
--END--
HOA: v1
States: 1
@ -402,7 +401,8 @@ HOA: v1
States: 10
Start: 2
AP: 1 "p1"
Acceptance: 2 Inf(1) | Inf(0)
acc-name: Buchi
Acceptance: 1 Inf(0)
properties: trans-labels explicit-labels state-acc
--BODY--
State: 0
@ -410,29 +410,29 @@ State: 0
[!0] 6
[0] 8
[0] 9
State: 1 {0 1}
State: 1
[t] 3
State: 2 {0 1}
State: 2
[0] 1
[!0] 5
State: 3 {0 1}
State: 3
[0] 0
[!0] 6
State: 4 {0 1}
State: 4 {0}
[0] 4
[!0] 6
State: 5 {0 1}
State: 5
[0] 3
[!0] 7
State: 6
[0] 0
[!0] 6
State: 7 {1}
State: 7
[0] 4
[!0] 6
State: 8
[0] 8
State: 9 {1}
State: 9 {0}
[0] 9
--END--
HOA: v1
@ -765,7 +765,7 @@ acc-name: Buchi
Acceptance: 1 Inf(0)
properties: trans-labels explicit-labels state-acc
--BODY--
State: 0 {0}
State: 0
[!0&1] 5
[!0&1] 7
State: 1

54
tests/python/simplacc.py Normal file
View file

@ -0,0 +1,54 @@
# -*- mode: python; coding: utf-8 -*-
# Copyright (C) 2020 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/>.
import spot
auts = list(spot.automata("""
HOA: v1 States: 2 Start: 0 AP: 2 "a" "b" Acceptance: 2 Inf(0) | Inf(1) --BODY--
State: 0 [1] 0 [0] 1 {0} State: 1 [0] 1 [1] 0 {1} --END--
HOA: v1 States: 2 Start: 0 AP: 2 "a" "b" Acceptance: 2 (Inf(0) | Inf(1)) &
Fin(0) --BODY-- State: 0 [1] 0 [0] 1 {0} State: 1 [0] 1 [1] 0 {1} --END--
HOA: v1 States: 2 Start: 0 AP: 2 "a" "b" Acceptance: 3 (Inf(0) | Inf(1)) &
(Fin(0) | Inf(2)) --BODY-- State: 0 [1] 0 [0] 1 {0} State: 1 [0] 1 {2} [1] 0
{1} --END--
HOA: v1 States: 2 Start: 0 AP: 2 "a" "b" Acceptance: 4 (Inf(0) |
(Inf(1)&(Inf(3)|Fin(2)))) --BODY-- State: 0 [1] 0 {3} [0] 1 {0} State: 1 [0] 1
{2} [1] 0 {1} --END--
"""))
res = []
for a in auts:
b = spot.simplify_acceptance(a)
assert b.equivalent_to(a)
res.append(str(b.get_acceptance()))
a.set_acceptance(a.num_sets(), a.get_acceptance().complement())
b = spot.simplify_acceptance(a)
assert b.equivalent_to(a)
res.append(str(b.get_acceptance()))
assert res == ['Inf(0)',
'Fin(0)',
'Inf(1) & Fin(0)',
'Fin(1) | Inf(0)',
'Inf(1) & (Fin(0) | Inf(2))',
'Fin(1) | (Fin(2) & Inf(0))',
'(Fin(1) | Inf(2)) & Inf(0)',
'Fin(0) | (Fin(2) & Inf(1))']