Commit 80ceca59 authored by Alexandre Duret-Lutz's avatar Alexandre Duret-Lutz
Browse files

Add LTL reductions for weak until.

* src/ltlvisit/basicreduce.cc: Perform the following reductions.
a U (b | Ga) = a W b
a W (b | Ga) = a W b
a U b | Ga = a W b
a U b | a W c = a W (b | c)
a W b | a W c = a W (b | c)
a U Ga = Ga
a W Ga = Ga
* src/ltltest/reduccmp.test: More tests.
parent 0fc0ea31
2010-04-12 Alexandre Duret-Lutz <adl@lrde.epita.fr>
Add LTL reductions for weak until.
* src/ltlvisit/basicreduce.cc: Perform the following reductions.
a U (b | Ga) = a W b
a W (b | Ga) = a W b
a U b | Ga = a W b
a U b | a W c = a W (b | c)
a W b | a W c = a W (b | c)
a U Ga = Ga
a W Ga = Ga
* src/ltltest/reduccmp.test: More tests.
2010-04-07 Alexandre Duret-Lutz <adl@lrde.epita.fr>
Add support for W (weak until) and M (strong release) operators.
......
......@@ -76,6 +76,7 @@ for x in ../reduccmp ../reductaustr; do
run 0 $x 'G(false)' 'false'
run 0 $x 'XGF(f)' 'GF(f)'
case $x in
*tau*);;
*)
......@@ -114,6 +115,11 @@ for x in ../reduccmp ../reductaustr; do
run 0 $x 'Gb W a' 'Gb|a'
run 0 $x 'Fb M Fa' 'Fa & Fb'
run 0 $x 'a U (b | G(a) | c)' 'a W (b | c)'
run 0 $x 'a U (G(a))' 'Ga'
run 0 $x '(a U b) | (a W c)' 'a W (b | c)'
run 0 $x '(a U b) | Ga' 'a W b'
;;
esac
......
......@@ -251,8 +251,6 @@ namespace spot
{
formula* f1 = bo->first();
formula* f2 = bo->second();
unop* fu1;
unop* fu2;
binop::type op = bo->op();
switch (op)
{
......@@ -267,56 +265,100 @@ namespace spot
case binop::M:
case binop::U:
case binop::R:
f1 = basic_reduce(f1);
f2 = basic_reduce(f2);
// a W false = Ga
if (op == binop::W && f2 == constant::false_instance())
{
result_ = unop::instance(unop::G, f1);
return;
}
// a M true = Fa
if (op == binop::M && f2 == constant::true_instance())
{
result_ = unop::instance(unop::F, f1);
return;
}
// a U false = false
// a U true = true
// a R false = false
// a R true = true
// a W true = true
// a M false = false
if (dynamic_cast<constant*>(f2))
{
result_ = f2;
f1->destroy();
return;
}
// X(a) U X(b) = X(a U b)
// X(a) R X(b) = X(a R b)
// X(a) W X(b) = X(a W b)
// X(a) M X(b) = X(a M b)
fu1 = dynamic_cast<unop*>(f1);
fu2 = dynamic_cast<unop*>(f2);
if (fu1 && fu2
&& fu1->op() == unop::X
&& fu2->op() == unop::X)
{
formula* ftmp = binop::instance(op,
basic_reduce(fu1->child()),
basic_reduce(fu2->child()));
result_ = unop::instance(unop::X, basic_reduce(ftmp));
f1->destroy();
f2->destroy();
ftmp->destroy();
return;
{
f1 = basic_reduce(f1);
f2 = basic_reduce(f2);
// a W false = Ga
if (op == binop::W && f2 == constant::false_instance())
{
result_ = unop::instance(unop::G, f1);
return;
}
// a M true = Fa
if (op == binop::M && f2 == constant::true_instance())
{
result_ = unop::instance(unop::F, f1);
return;
}
// a U false = false
// a U true = true
// a R false = false
// a R true = true
// a W true = true
// a M false = false
if (dynamic_cast<constant*>(f2))
{
result_ = f2;
f1->destroy();
return;
}
// X(a) U X(b) = X(a U b)
// X(a) R X(b) = X(a R b)
// X(a) W X(b) = X(a W b)
// X(a) M X(b) = X(a M b)
unop* fu1 = dynamic_cast<unop*>(f1);
unop* fu2 = dynamic_cast<unop*>(f2);
if (fu1 && fu2
&& fu1->op() == unop::X
&& fu2->op() == unop::X)
{
formula* ftmp = binop::instance(op,
basic_reduce(fu1->child()),
basic_reduce(fu2->child()));
result_ = unop::instance(unop::X, basic_reduce(ftmp));
f1->destroy();
f2->destroy();
ftmp->destroy();
return;
}
if (op == binop::U || op == binop::W)
{
// a U Ga = Ga
// a W Ga = Ga
if (fu2 && fu2->op() == unop::G && fu2->child() == f1)
{
result_ = f2;
f1->destroy();
return;
}
// a U (b | G(a)) = a W b
// a W (b | G(a)) = a W b
multop* fm2 = dynamic_cast<multop*>(f2);
if (fm2 && fm2->op() == multop::Or)
{
int s = fm2->size();
for (int i = 0; i < s; ++i)
{
unop* c = dynamic_cast<unop*>(fm2->nth(i));
if (c && c->op() == unop::G && c->child() == f1)
{
multop::vec* v = new multop::vec;
v->reserve(s - 1);
int j;
for (j = 0; j < i; ++j)
v->push_back(fm2->nth(j)->clone());
// skip j=i
for (++j; j < s; ++j)
v->push_back(fm2->nth(j)->clone());
result_ =
binop::instance(binop::W, f1,
multop::instance(multop::Or,
v));
f2->destroy();
return;
}
}
}
}
result_ = binop::instance(op, f1, f2);
return;
}
result_ = binop::instance(op, f1, f2);
return;
}
/* Unreachable code. */
assert(0);
......@@ -485,6 +527,35 @@ namespace spot
// F(a) | F(b) = F(a | b)
tmpF->push_back(uo->child()->clone());
}
else if (uo->op() == unop::G)
{
// G(a) | (a U b) = a W b
// G(a) | (a W b) = a W b
formula* a = uo->child();
bool rewritten = false;
for (multop::vec::iterator j = i;
j != res->end(); ++j)
{
if (!*j)
continue;
binop* b = dynamic_cast<binop*>(*j);
if (b && (b->op() == binop::U
|| b->op() == binop::W)
&& b->first() == a)
{
binop* r =
binop::instance(binop::W,
a->clone(),
b->second()->clone());
tmpOther->push_back(r);
(*j)->destroy();
*j = 0;
rewritten = true;
}
}
if (!rewritten)
tmpOther->push_back(uo->clone());
}
else
{
tmpOther->push_back((*i)->clone());
......@@ -492,22 +563,36 @@ namespace spot
}
else if (bo)
{
if (bo->op() == binop::U)
if (bo->op() == binop::U || bo->op() == binop::W)
{
// (a U b) | (a U c) = a U (b | c)
// (a W b) | (a U c) = a W (b | c)
bool weak = false;
formula* ftmp = bo->first();
multop::vec* tmpUright = new multop::vec;
multop::vec* right = new multop::vec;
for (multop::vec::iterator j = i; j != res->end();
j++)
{
if (!*j)
continue;
// (a U b) | Ga = a W b.
// (a W b) | Ga = a W b.
unop* uo2 = dynamic_cast<unop*>(*j);
if (uo2 && uo2->op() == unop::G
&& uo2->child() == ftmp)
{
(*j)->destroy();
*j = 0;
weak = true;
}
binop* bo2 = dynamic_cast<binop*>(*j);
if (bo2 && bo2->op() == binop::U
if (bo2 && (bo2->op() == binop::U ||
bo2->op() == binop::W)
&& ftmp == bo2->first())
{
tmpUright
->push_back(bo2->second()->clone());
if (bo2->op() == binop::W)
weak = true;
right->push_back(bo2->second()->clone());
if (j != i)
{
(*j)->destroy();
......@@ -515,11 +600,12 @@ namespace spot
}
}
}
tmpU->push_back(binop::instance(binop::U,
tmpU->push_back(binop::instance(weak ?
binop::W : binop::U,
ftmp->clone(),
multop::
instance(multop::Or,
tmpUright)));
right)));
}
else if (bo->op() == binop::R)
{
......@@ -596,7 +682,6 @@ namespace spot
else
delete tmpU;
if (!tmpR->empty())
tmpOther->push_back(multop::instance(mo->op(), tmpR));
else
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment