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Fix a case caught by the random formula generator.

Browse source 
* src/ltlvisit/simplify.cc (ltl_simplifier): Since we are processing
the formula bottom-up, don't assume all trivial simplification have
been done.
* src/ltltest/reduccmp.test: More tests.
This commit is contained in:
Alexandre Duret-Lutz 2011-08-22 22:14:36 +02:00
parent ca2fe4f3f8
commit ca686cb07e
2 changed files with 35 additions and 8 deletions
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7
src/ltltest/reduccmp.test
View file

@ -66,7 +66,7 @@ for x in ../reduccmp ../reductaustr; do
run 0 $x 'a | (b U a) | a' '(b U a)'
run 0 $x 'a U (b U a)' '(b U a)'
# Basics reduction
# Basic reductions
run 0 $x 'X(true)' 'true'
run 0 $x 'X(false)' 'false'
run 0 $x 'F(true)' 'true'
@ -147,6 +147,11 @@ for x in ../reduccmp ../reductaustr; do
run 0 $x 'b R Ga' 'Ga'
run 0 $x 'b R FGa' 'FGa'
run 0 $x 'G(!a M a) M 1' '0'
run 0 $x 'G(!a M a) U 1' '1'
run 0 $x 'a R (!a M a)' '0'
run 0 $x 'a W (!a M a)' 'Ga'
# Syntactic implication
run 0 $x '(a & b) R (a R c)' '(a & b)R c'
run 0 $x 'a R ((a & b) R c)' '(a & b)R c'

36
src/ltlvisit/simplify.cc
View file

@ -540,6 +540,14 @@ namespace spot
formula*
simplify_recursively(const formula* f, ltl_simplifier_cache* c);
constant*
is_constant(formula* f)
{
if (f->kind() != formula::Constant)
return 0;
return static_cast<constant*>(f);
}
unop*
is_unop(formula* f, unop::type op)
{
@ -868,8 +876,11 @@ namespace spot
break;
case unop::X:
// X(constant) = constant is a trivial identity
assert(result_->kind() != formula::Constant);
// X(constant) = constant is a trivial identity, but if
// the constant has been constructed by recurse() this
// identity has not been applied.
if (is_constant(result_))
return;
// XGF(f) = GF(f) and XFG(f)=FG(f)
if (is_GF(result_) || is_FG(result_))
@ -885,8 +896,11 @@ namespace spot
break;
case unop::F:
// F(constant) = constant is a trivial identity.
assert(result_->kind() != formula::Constant);
// F(constant) = constant is a trivial identity, but if
// the constant has been constructed by recurse() this
// identity has not been applied.
if (is_constant(result_))
return;
// If f is a pure eventuality formula then F(f)=f.
if (opt_.event_univ && result_->is_eventual())
@ -940,8 +954,11 @@ namespace spot
break;
case unop::G:
// G(constant) = constant is a trivial identity
assert(result_->kind() != formula::Constant);
// G(constant) = constant is a trivial identity, but if
// the constant has been constructed by recurse() this
// identity has not been applied.
if (is_constant(result_))
return;
// If f is a pure universality formula then G(f)=f.
if (opt_.event_univ && result_->is_universal())
@ -1263,7 +1280,12 @@ namespace spot
// a R true = true
// a W true = true
// a M false = false
assert(f2->kind() != formula::Constant);
if (is_constant(f2))
{
result_ = f2;
f1->destroy();
return;
}
// Same effect as dynamic_cast<unop*>, only faster.
unop* fu1 =