Commit b726d78c authored by Alexandre Duret-Lutz's avatar Alexandre Duret-Lutz

tl: new simplification rules

Related to issue #385.

* doc/tl/tl.tex, NEWS: Document the rules.
* spot/tl/simplify.cc: Implement the rules.
* tests/core/reduccmp.test, tests/core/ltl2tgba2.test: Add tests.
* tests/core/degenscc.test: Adjust.
parent 066133b8
......@@ -62,6 +62,12 @@ New in spot 2.7.4.dev (not yet released)
- spot::relabel_apply() make it easier to reverse the effect
of spot::relabel() or spot::relabel_bse() on formula.
- The LTL simplifier learned the following optional rules:
F(G(a | Fb)) = FGa | GFb (if option "favor_event_univ")
G(F(a | Gb)) = GFa | FGb (if option "favor_event_univ")
F(G(a & Fb) = FGa & GFb (unless option "reduce_size_strictly")
G(F(a & Gb)) = GFa & FGb (unless option "reduce_size_strictly")
New in spot 2.7.4 (2019-04-27)
Bugs fixed:
......
......@@ -1451,11 +1451,13 @@ instead of $\equiv$, and they can be disabled by setting the
The following are simplification rules for unary operators (applied
from left to right, as usual):
\begin{align*}
\X\F\G f & \equiv \F\G f & \F\X f & \equiv \X\F f & \G\X f & \equiv \X\G f \\
\X\G\F f & \equiv \G\F f & \F(f\U g) & \equiv \F g & \G(f \R g) & \equiv \G g \\
& & \F(f\M g) & \equiv \F (f\AND g) & \G(f \W g) & \equiv \G(f\OR g) \\
& & \F\G(f\AND \X g) & \equiv \F\G(f\AND g) & \G\F(f\OR \X g) & \equiv \G\F(f\OR g) \\
& & \F\G(f\AND \G g) & \equiv \F\G(f\AND g) & \G\F(f\OR \F g) & \equiv \G\F(f\OR g) \\
\X\F\G f & \equiv \F\G f & \F(f\U g) & \equiv \F g & \G(f \R g) & \equiv \G g \\
\X\G\F f & \equiv \G\F f & \F(f\M g) & \equiv \F (f\AND g) & \G(f \W g) & \equiv \G(f\OR g) \\
\F\X f & \equiv \X\F f & \F\G(f\AND \X g) & \equiv \F\G(f\AND g) & \G\F(f\OR \X g) & \equiv \G\F(f\OR g) \\
\G\X f & \equiv \X\G f & \F\G(f\AND \G g) & \equiv \F\G(f\AND g) & \G\F(f\OR \F g) & \equiv \G\F(f\OR g) \\
& & \F\G(f\OR\G g) & \equiv \F(\G f\OR\G g) & \G\F(f\AND\F g) & \equiv \G(\F f\AND\F g) \\
& & \F\G(f\AND\F g) & \equiV \F\G f\AND\G\F g & \G\F(f\AND\G g) & \equiV \G\F f\AND\F\G g \\
& & \F\G(f\OR\F g) & \equivEU \F\G f\OR\G\F g & \G\F(f\OR\G g) & \equivEU \G\F f\OR\F\G g
\end{align*}
\begin{align*}
\G(f_1\OR\ldots\OR f_n \OR \G\F(g_1)\OR\ldots\OR \G\F(g_m)) & \equiv \G(f_1\OR\ldots\OR f_n)\OR \G\F(g_1\OR\ldots\OR g_m)
......
......@@ -913,16 +913,21 @@ namespace spot
if (opt_.event_univ && c.is_eventual())
return c;
auto g_in_f = [this](formula g, std::vector<formula>* to)
auto g_in_f = [this](formula g, std::vector<formula>* to,
std::vector<formula>* eventual = nullptr)
{
if (g[0].is(op::Or))
{
mospliter s2(mospliter::Split_Univ, g[0], c_);
mospliter s2(mospliter::Split_Univ |
(eventual ? mospliter::Split_Event : 0),
g[0], c_);
for (formula e: *s2.res_Univ)
to->push_back(e.is(op::X) ? e[0] : e);
to->push_back
(unop_multop(op::G, op::Or,
std::move(*s2.res_other)));
if (eventual)
std::swap(*s2.res_Event, *eventual);
}
else
{
......@@ -947,13 +952,37 @@ namespace spot
if (c.is(op::X))
return recurse(unop_unop(op::X, op::F, c[0]));
// G(F(a & Fb)) = G(Fa & Fb)
// F(G(a | Gb)) = F(Ga | Gb)
// F(G(a | Fb)) = FGa | GFb // opt_.favor_event_univ
if (c.is({op::G, op::Or}))
{
std::vector<formula> toadd;
g_in_f(c, &toadd);
std::vector<formula> toadd, eventual;
g_in_f(c, &toadd,
opt_.favor_event_univ ? &eventual : nullptr);
formula res = unop_multop(op::F, op::Or,
std::move(toadd));
if (!eventual.empty())
{
formula ev = unop_multop(op::G, op::Or,
std::move(eventual));
res = formula::Or({res, ev});
}
if (res != f)
return recurse(res);
}
// F(G(a & Fb) = FGa & GFb // !opt_.reduce_size_strictly
if (c.is({op::G, op::And}) && !opt_.reduce_size_strictly)
{
mospliter s2(mospliter::Split_Event, c[0], c_);
for (formula& e: *s2.res_Event)
while (e.is(op::X))
e = e[0];
formula fg = unop_unop_multop(op::F, op::G, op::And,
std::move(*s2.res_other));
formula gf = unop_multop(op::G, op::And,
std::move(*s2.res_Event));
formula res = formula::And({fg, gf});
if (res != f)
return recurse(res);
}
......@@ -1077,16 +1106,21 @@ namespace spot
if (opt_.event_univ && c.is_universal())
return c;
auto f_in_g = [this](formula f, std::vector<formula>* to)
auto f_in_g = [this](formula f, std::vector<formula>* to,
std::vector<formula>* univ = nullptr)
{
if (f[0].is(op::And))
{
mospliter s2(mospliter::Split_Event, f[0], c_);
mospliter s2(mospliter::Split_Event |
(univ ? mospliter::Split_Univ : 0),
f[0], c_);
for (formula e: *s2.res_Event)
to->push_back(e.is(op::X) ? e[0] : e);
to->push_back
(unop_multop(op::F, op::And,
std::move(*s2.res_other)));
if (univ)
std::swap(*s2.res_Univ, *univ);
}
else
{
......@@ -1112,12 +1146,36 @@ namespace spot
return recurse(unop_unop(op::X, op::G, c[0]));
// G(F(a & Fb)) = G(Fa & Fb)
// G(F(a & Gb)) = GFa & FGb // !opt_.reduce_size_strictly
if (c.is({op::F, op::And}))
{
std::vector<formula> toadd;
f_in_g(c, &toadd);
std::vector<formula> toadd, univ;
f_in_g(c, &toadd,
opt_.reduce_size_strictly ? nullptr : &univ);
formula res = unop_multop(op::G, op::And,
std::move(toadd));
if (!univ.empty())
{
formula un = unop_multop(op::F, op::And,
std::move(univ));
res = formula::And({res, un});
}
if (res != f)
return recurse(res);
}
// G(F(a | Gb)) = GFa | FGb // opt_.favor_event_univ
if (c.is({op::F, op::Or}) && opt_.favor_event_univ)
{
mospliter s2(mospliter::Split_Univ, c[0], c_);
for (formula& u: *s2.res_Univ)
while (u.is(op::X))
u = u[0];
formula gf = unop_unop_multop(op::G, op::F, op::Or,
std::move(*s2.res_other));
formula fg = unop_multop(op::F, op::Or,
std::move(*s2.res_Univ));
formula res = formula::Or({gf, fg});
if (res != f)
return recurse(res);
}
......
#!/bin/sh
# -*- coding: utf-8 -*-
# Copyright (C) 2017 Laboratoire de Recherche et Développement de
# Copyright (C) 2017, 2019 Laboratoire de Recherche et Développement de
# l'Epita (LRDE).
#
# This file is part of Spot, a model checking library.
......@@ -28,28 +28,34 @@ set -e
# The following cases were found with
#
# % randltl -n -1 3 | ltl2tgba | autfilt --acc-sets=3.. |
# autfilt -B --stats='%C,%c,%M' | awk -F, '{ if ($1 < $2) { print $0; } }'
#
# before patching degeneralize, but today replacing -B by -Bx'!degen-remscc'
# should do the same.
# autfilt -Bx'!degen-remscc' --stats='%C,%c,%M' |
# awk -F, '{ if ($1 < $2) { print $0; } }'
cat >input <<EOF
p2 & GF(G(p0 & !p1) | (F!p0 & Fp1))
GF((Fp2 & X((p0 & Gp1) | (!p0 & F!p1))) | (G!p2 & X((p0 & F!p1) | (!p0 & Gp1))))
GF(p0 | GF((p2 M p1) | (Fp1 & F!p0) | G(p0 & !p1)))
((Gp2&FG((Gp1&Xp0)|(F!p1&X!p0)))|(F!p2 & GF((Gp1 & X!p0)|(Xp0 & F!p1)))) W !p0
((Gp2&FG((Gp1&Xp0)|(F!p1&X!p0)))|(F!p2 & GF((Gp1 & X!p0) | (Xp0 & F!p1)))) W !p0
G(Fp0 & (F!p1 U (G!p2 M !p0)))
G(((Fp1 & (p1 W Fp0)) | (G!p1 & (!p1 M G!p0))) M FG!p2)
Xp0 R F((p0 & FG(Gp2 U p1)) | (!p0 & GF(F!p2 R !p1)))
GF(p0 & (((p1 & Fp2) | (!p1 & G!p2)) M Gp1))
F(G!p0 | GF((Gp0 & (!p2 R !p1)) | ((p2 U p1) & F!p0)))
p1|X(p1 R F((((p2&G!p0)|(!p2&Fp0))&FGp0)|(((p2 & Fp0) | (!p2 & G!p0)) & GF!p0)))
G(!p1 | (!p2 & F!p1) | (GFp2 U p0))
X(p1 | GF((Fp2 & F!p1) | G(p1 & !p2)))
GF((Fp2&(p0 U((p1&GFp0)|(!p1&FG!p0))))|(G!p2&(!p0 R((p1&FG!p0)|(!p1&GFp0)))))
GF((XFp1 & ((p0 & G!p2) | (!p0 & Fp2))) | (XG!p1 & ((p0 & Fp2) | (!p0 & G!p2))))
F(!p2 | GF((Fp0 & ((p0 & Gp1)|(!p0&F!p1)))|(G!p0&((p0&F!p1)|(!p0&Gp1)))))
G(XF((p2 & F!p1) | (!p2 & Gp1)) | (p1 & Fp0))
!p0 | GF((p1 & (Xp2 W Gp2)) | (!p1 & (X!p2 M F!p2)))
G!p0 | G((Fp1 U p2) & F!p2)
EOF
# We want to make sure the degeneralized automaton as less SCCs
# We want to make sure the degeneralized automaton has fewer SCCs
# (it can be less if the simulation on the BA is lukier than on the TGBA)
ltl2tgba < input | autfilt -B --stats=": '%M'; test %C -ge %c" > test.sh
sh -x -e test.sh
# Make sur that this degen-remscc optimizition is actually doing something.
# Make sure that this degen-remscc optimizition is actually doing something.
# The following test could fail in the future if we improve the translation
# of some of these formulas. In that case, regenerate the list of test
# formula using the command displayed above.
......
......@@ -365,22 +365,31 @@ diff output expected
# The first four formulas appear in a NEWS entry for Spot 2.6
# The 5th one is from issue #267.
# The 6th one is from issue #358.
# formula 7-12 are from issue #385.
cat >formulas <<EOF
GF((a & XXa) | (!a & XX!a)), 4,8, 4,8, 6,14, 7,14
GF((a & XXXa) | (!a & XXX!a)), 7,14, 8,16, 8,18, 15,30
GF(((a & Xb) | XXc) & Xd), 4,64, 4,64, 5,80, 5,80
GF((b | Fa) & (b R Xb)), 2,4, 2,4, 3,6, 3,12
G(F(a & Xa) & F(a & X!a)), 2,4, 2,4, 4,8, 4,8
G(!p0 & F(p1 & XG!p1)), 1,0, 1,0, 1,0, 1,0
GF((a & XXa) | (!a & XX!a)), 4,8, 4,8, 6,14, 7,14, 4,8
GF((a & XXXa) | (!a & XXX!a)), 7,14, 8,16, 8,18, 15,30, 8,16
GF(((a & Xb) | XXc) & Xd), 4,64, 4,64, 5,80, 5,80, 4,64
GF((b | Fa) & (b R Xb)), 2,4, 2,4, 3,6, 3,12, 2,4
G(F(a & Xa) & F(a & X!a)), 2,4, 2,4, 4,8, 4,8, 3,6
G(!p0 & F(p1 & XG!p1)), 1,0, 1,0, 1,0, 1,0, 1,0
FG(a | Fb), 3,15, 3,15, 3,15, 3,15, 1,4
FG(a & Fb), 2,7, 2,7, 3,9, 3,9, 1,4
GF(a & Gb), 2,7, 2,7, 3,9, 3,9, 1,4
GF(a | Gb), 2,7, 2,7, 3,12, 3,12, 1,4
Ge | GF(Ge & X(c & Fd)), 4,31, 4,31, 6,39, 6,39, 2,16
F(GF(b & Gc) | Ge), 3,22, 3,22, 4,26, 4,26, 1,8
EOF
# Call perl in the middle of all this to make sure
# \r is removed fom %>. Issue #380.
ltl2tgba -Fformulas/1 --stats='%f, %s,%t' |
ltl2tgba -D -F-/1 --stats='%f,%>, %s,%t' |
perl -pi -e 's/$/\r/' |
ltl2tgba -B -F-/1 --stats='%f,%>, %s,%t' |
ltl2tgba -BD -F-/1 --stats='%f,%>, %s,%t' > output
ltlfilt -Fformulas/1 --stats='%f,%f,%>' |
ltl2tgba -F-/2 --stats='%<,%<, %s,%t' |
ltl2tgba -D -F-/2 --stats='%<,%<,%>, %s,%t' |
perl -p -e 's/$/\r/' |
ltl2tgba -B -F-/2 --stats='%<,%<,%>, %s,%t' |
ltl2tgba -BD -F-/2 --stats='%<,%<,%>, %s,%t' |
ltl2tgba -GD -F-/2 --stats='%<,%>, %s,%t' > output
diff formulas output
......
......@@ -335,6 +335,18 @@ Xa&Xb&GFc&GFd&Ge, X(a&b&G(Fc&Fd))&Ge
GFc|GFd|FGe|FGf, F(GF(c|d)|Ge|Gf)
G(GFc|GFd|FGe|FGf), F(GF(c|d)|Ge|Gf)
F(G(a | Gb)), F(Ga | Gb)
G(F(a & Fb)), G(Fa & Fb)
# These two are not reduced by default
F(G(a | Fb)), F(G(a | Fb))
G(F(a | Gb)), G(F(a | Gb))
# issue #385
F(G(a & Fb)), G(Fb & FGa)
G(F(a & Gb)), G(Fa & FGb)
Ge | XGF(Ge & X(c & Fd)), Ge | G(Fd & FGe & Fc)
G!GXXe -> GF(b & c & Gc), F(G(Fb & FGc) | Ge)
# Because reduccmp will translate the formula,
# this also check for an old bug in ltl2tgba_fm.
{(c&!c)[->0..1]}!, 0
......
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