Move language containment into ltl_simplifier.
* src/ltlvisit/simplify.cc: Integrate the tau03 containment rules. * src/ltlvisit/simplify.hh: Add options to select simplifications. * src/ltlvisit/reduce.cc (reduce): Do not call reduce_tau03(). * src/ltlvisit/contain.cc (reduce_tau03_visitor): Remove. (reduce_tau03): Implement it using ltl_simplifier.
This commit is contained in:
Alexandre Duret-Lutz
parent
82b42494db
commit
1087c62356
4 changed files with 442 additions and 539 deletions
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@ -22,6 +22,7 @@
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// 02111-1307, USA.
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#include "contain.hh"
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#include "simplify.hh"
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#include "tunabbrev.hh"
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#include "ltlast/unop.hh"
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#include "ltlast/binop.hh"
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@ -144,271 +145,16 @@ namespace spot
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}
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namespace
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{
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struct reduce_tau03_visitor : public clone_visitor {
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bool stronger;
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language_containment_checker* lcc;
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reduce_tau03_visitor(bool stronger,
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language_containment_checker* lcc)
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: stronger(stronger), lcc(lcc)
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{
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}
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void
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visit(unop* uo)
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{
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formula* a = recurse(uo->child());
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switch (uo->op())
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{
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case unop::X:
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// if X(a) = a, then keep only a !
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if (stronger && lcc->equal(a, uo))
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{
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result_ = a;
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break;
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}
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default:
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result_ = unop::instance(uo->op(), a);
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}
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}
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void
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visit(binop* bo)
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{
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formula* a = recurse(bo->first());
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formula* b = recurse(bo->second());
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switch (bo->op())
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{
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case binop::U:
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// if (a U b) => b, then keep b !
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if (stronger && lcc->contained(bo, b))
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{
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a->destroy();
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result_ = b;
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}
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// if a => b, then a U b = b.
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else if ((!stronger) && lcc->contained(a, b))
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{
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a->destroy();
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result_ = b;
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}
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// if !a => b, then a U b = Fb
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else if (lcc->neg_contained(a, b))
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{
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a->destroy();
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result_ = unop::instance(unop::F, b);
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}
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else
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{
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result_ = binop::instance(binop::U, a, b);
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}
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break;
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case binop::W:
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// if (a W b) => b, then keep b !
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if (stronger && lcc->contained(bo, b))
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{
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a->destroy();
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result_ = b;
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}
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// if a => b, then a W b = b.
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else if ((!stronger) && lcc->contained(a, b))
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{
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a->destroy();
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result_ = b;
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}
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// if !a => b, then a W b = 1
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else if (lcc->neg_contained(a, b))
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{
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a->destroy();
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b->destroy();
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result_ = constant::true_instance();
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}
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else
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{
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result_ = binop::instance(binop::W, a, b);
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}
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break;
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case binop::R:
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// if b => a, then a R b = b.
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if (lcc->contained(b, a))
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{
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a->destroy();
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result_ = b;
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}
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// if a => !b, then a R b = Gb
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else if (lcc->contained_neg(a, b))
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{
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a->destroy();
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result_ = unop::instance(unop::G, b);
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}
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else
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{
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result_ = binop::instance(binop::R, a, b);
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}
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break;
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case binop::M:
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// if b => a, then a M b = b.
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if (lcc->contained(b, a))
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{
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a->destroy();
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result_ = b;
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}
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// if a => !b, then a M b = 0
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else if (lcc->contained_neg(a, b))
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{
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a->destroy();
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b->destroy();
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result_ = constant::false_instance();
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}
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else
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{
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result_ = binop::instance(binop::M, a, b);
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}
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break;
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default:
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result_ = binop::instance(bo->op(), a, b);
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}
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}
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void
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visit(automatop*)
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{
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assert(0);
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}
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void
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visit(multop* mo)
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{
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multop::vec* res = new multop::vec;
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unsigned mos = mo->size();
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for (unsigned i = 0; i < mos; ++i)
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res->push_back(recurse(mo->nth(i)));
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result_ = 0;
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bool changed = false;
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switch (mo->op())
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{
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case multop::Or:
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for (unsigned i = 0; i < mos; ++i)
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{
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if (!(*res)[i])
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continue;
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for (unsigned j = i + 1; j < mos; ++j)
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{
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if (!(*res)[j])
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continue;
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// if !i => j, then i|j = true
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if (lcc->neg_contained((*res)[i], (*res)[j]))
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{
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result_ = constant::true_instance();
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goto constant_;
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}
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// if i => j, then i|j = j
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else if (lcc->contained((*res)[i], (*res)[j]))
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{
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(*res)[i]->destroy();
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(*res)[i] = 0;
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changed = true;
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break;
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}
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// if j => i, then i|j = i
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else if (lcc->contained((*res)[j], (*res)[i]))
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{
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(*res)[j]->destroy();
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(*res)[j] = 0;
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changed = true;
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}
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}
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}
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break;
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case multop::And:
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for (unsigned i = 0; i < mos; ++i)
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{
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if (!(*res)[i])
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continue;
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for (unsigned j = i + 1; j < mos; ++j)
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{
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if (!(*res)[j])
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continue;
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// if i => !j, then i&j = false
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if (lcc->contained_neg((*res)[i], (*res)[j]))
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{
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result_ = constant::false_instance();
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goto constant_;
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}
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// if i => j, then i&j = i
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else if (lcc->contained((*res)[i], (*res)[j]))
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{
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(*res)[j]->destroy();
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(*res)[j] = 0;
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changed = true;
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}
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// if j => i, then i&j = j
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else if (lcc->contained((*res)[j], (*res)[i]))
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{
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(*res)[i]->destroy();
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(*res)[i] = 0;
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changed = true;
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break;
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}
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}
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}
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break;
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case multop::Concat:
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case multop::Fusion:
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case multop::AndNLM:
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break;
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}
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if (changed)
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{
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multop::vec* nres = new multop::vec;
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for (unsigned i = 0; i < mos; ++i)
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if ((*res)[i])
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nres->push_back((*res)[i]);
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delete res;
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res = nres;
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}
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result_ = multop::instance(mo->op(), res);
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return;
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constant_:
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for (unsigned i = 0; i < mos; ++i)
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if ((*res)[i])
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(*res)[i]->destroy();
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delete res;
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}
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formula*
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recurse(formula* f)
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{
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if (!f->is_psl_formula())
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return f->clone();
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reduce_tau03_visitor v(stronger, lcc);
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const_cast<formula*>(f)->accept(v);
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return v.result();
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}
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};
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}
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formula*
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reduce_tau03(const formula* f, bool stronger)
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{
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if (!f->is_psl_formula())
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return f->clone();
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bdd_dict b;
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reduce_tau03_visitor v(stronger,
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new language_containment_checker(&b,
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true, true,
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false, false));
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// reduce_tau03_visitor does not handle Xor, Implies, and Equiv.
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f = unabbreviate_ltl(f);
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const_cast<formula*>(f)->accept(v);
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f->destroy();
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delete v.lcc;
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return v.result();
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ltl_simplifier_options opt(false, false, false,
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true, stronger);
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ltl_simplifier simpl(opt);
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return simpl.simplify(f);
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}
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}
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}
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@ -28,7 +28,6 @@
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#include "lunabbrev.hh"
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#include "simpfg.hh"
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#include "nenoform.hh"
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#include "contain.hh"
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#include "simplify.hh"
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namespace spot
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@ -73,20 +72,8 @@ namespace spot
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f2->destroy();
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f2 = f1;
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f1 = simplifier.simplify(f2);
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f = simplifier.simplify(f2);
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f2->destroy();
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f2 = f1;
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if (opt & (Reduce_Containment_Checks
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| Reduce_Containment_Checks_Stronger))
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{
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formula* f1 =
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reduce_tau03(f2,
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opt & Reduce_Containment_Checks_Stronger);
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f2->destroy();
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f2 = f1;
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}
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f = f2;
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}
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prev->destroy();
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@ -18,6 +18,14 @@
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// Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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// 02111-1307, USA.
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#include <iostream>
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//#define TRACE
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#ifdef TRACE
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#define trace std::cerr
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#else
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#define trace while (0) std::cerr
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#endif
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#include "simplify.hh"
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#include "misc/hash.hh"
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@ -25,6 +33,8 @@
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#include "ltlast/allnodes.hh"
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#include "ltlast/visitor.hh"
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#include "ltlvisit/syntimpl.hh"
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#include "ltlvisit/contain.hh"
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#include "ltlvisit/tostring.hh"
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#include <cassert>
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namespace spot
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@ -40,8 +50,10 @@ namespace spot
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typedef Sgi::hash_map<const formula*, bdd,
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ptr_hash<formula> > f2b_map;
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public:
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bdd_dict dict;
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ltl_simplifier_options options;
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syntactic_implication_cache syntimpl;
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language_containment_checker lcc;
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~ltl_simplifier_cache()
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{
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@ -79,11 +91,14 @@ namespace spot
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}
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ltl_simplifier_cache()
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: lcc(&dict, true, true, false, false)
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{
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}
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ltl_simplifier_cache(ltl_simplifier_options opt) : options(opt)
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ltl_simplifier_cache(ltl_simplifier_options opt)
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: options(opt), lcc(&dict, true, true, false, false)
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{
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opt.containment_checks |= opt.containment_checks_stronger;
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}
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// Convert a Boolean formula into a BDD for easier comparison.
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@ -193,19 +208,126 @@ namespace spot
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nenoform_[orig->clone()] = nenoform->clone();
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}
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// Return true if f1 < f2 (i.e. f1 implies f2 syntactically)
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// Return true iff the option set (syntactic implication
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// or containment checks) allow to prove that f1 => f2.
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bool
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implication(const formula* f1, const formula* f2)
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{
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return (options.synt_impl && syntactic_implication(f1, f2))
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|| (options.containment_checks && contained(f1, f2));
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}
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// Return true if f1 => f2 syntactically
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bool
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syntactic_implication(const formula* f1, const formula* f2)
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{
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// We cannot run syntactic_implication on SERE formulae,
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// except on Boolean formulae.
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if (f1->is_sere_formula() && !f1->is_boolean())
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return false;
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if (f2->is_sere_formula() && !f2->is_boolean())
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return false;
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return syntimpl.syntactic_implication(f1, f2);
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}
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// If right==false, true if !f1 < f2, false otherwise.
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// If right==true, true if f1 < !f2, false otherwise.
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bool syntactic_implication_neg(const formula* f1, const formula* f2,
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// Return true if f1 => f2
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bool
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contained(const formula* f1, const formula* f2)
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{
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if (!f1->is_psl_formula() || !f2->is_psl_formula())
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return false;
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return lcc.contained(f1, f2);
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}
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// If right==false, true if !f1 => f2, false otherwise.
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// If right==true, true if f1 => !f2, false otherwise.
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bool
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syntactic_implication_neg(const formula* f1, const formula* f2,
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bool right)
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{
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return syntimpl.syntactic_implication_neg(f1, f2, right);
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// We cannot run syntactic_implication_neg on SERE formulae,
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// except on Boolean formulae.
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if (f1->is_sere_formula() && !f1->is_boolean())
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return false;
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if (f2->is_sere_formula() && !f2->is_boolean())
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return false;
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trace << "[SIN] Does " << (right ? "(" : "!(")
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<< to_string(f1) << ") implies "
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<< (right ? "!(" : "(") << to_string(f2) << ") ?"
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<< std::endl;
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if (syntimpl.syntactic_implication_neg(f1, f2, right))
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{
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trace << "[SIN] Yes" << std::endl;
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return true;
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}
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else
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{
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trace << "[SIN] No" << std::endl;
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return false;
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}
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}
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// Return true if f1 => !f2
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bool contained_neg(const formula* f1, const formula* f2)
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{
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if (!f1->is_psl_formula() || !f2->is_psl_formula())
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return false;
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trace << "[CN] Does (" << to_string(f1) << ") implies !("
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<< to_string(f2) << ") ?" << std::endl;
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if (lcc.contained_neg(f1, f2))
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{
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trace << "[CN] Yes" << std::endl;
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return true;
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}
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else
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{
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trace << "[CN] No" << std::endl;
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return false;
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}
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}
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// Return true if f1 => !f2
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bool neg_contained(const formula* f1, const formula* f2)
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{
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if (!f1->is_psl_formula() || !f2->is_psl_formula())
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return false;
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trace << "[NC] Does (" << to_string(f1) << ") implies !("
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<< to_string(f2) << ") ?" << std::endl;
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if (lcc.neg_contained(f1, f2))
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{
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trace << "[NC] Yes" << std::endl;
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return true;
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}
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else
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{
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trace << "[NC] No" << std::endl;
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return false;
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}
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}
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// Return true iff the option set (syntactic implication
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// or containment checks) allow to prove that
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// - !f2 => f2 (case where right=false)
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// - f1 => !f2 (case where right=true)
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bool
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implication_neg(const formula* f1, const formula* f2, bool right)
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{
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trace << "[IN] Does " << (right ? "(" : "!(")
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<< to_string(f1) << ") implies "
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<< (right ? "!(" : "(") << to_string(f2) << ") ?"
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<< std::endl;
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if ((options.synt_impl && syntactic_implication_neg(f1, f2, right))
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|| (options.containment_checks && right && contained_neg(f1, f2))
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|| (options.containment_checks && !right && neg_contained(f1, f2)))
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{
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trace << "[IN] Yes" << std::endl;
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return true;
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}
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else
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{
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trace << "[IN] No" << std::endl;
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return false;
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}
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}
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const formula*
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@ -788,10 +910,13 @@ namespace spot
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init();
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multop::vec::const_iterator end = v->end();
|
||||
for (multop::vec::const_iterator i = v->begin(); i < end; ++i)
|
||||
{
|
||||
if (*i) // skip null pointers left by previous simplifications
|
||||
{
|
||||
process(*i);
|
||||
(*i)->destroy();
|
||||
}
|
||||
}
|
||||
delete v;
|
||||
}
|
||||
|
||||
|
|
@ -891,10 +1016,17 @@ namespace spot
|
|||
// XGF(f) = GF(f) and XFG(f) = FG(f)
|
||||
// The former comes from Somenzi&Bloem (CAV'00).
|
||||
// It's not clear why they do not list the second.
|
||||
if (is_GF(result_) || is_FG(result_))
|
||||
if (opt_.reduce_basics &&
|
||||
(is_GF(result_) || is_FG(result_)))
|
||||
return;
|
||||
}
|
||||
|
||||
|
||||
// If Xa = a, keep only a.
|
||||
if (opt_.containment_checks_stronger
|
||||
&& c_->lcc.equal(result_, uo))
|
||||
return;
|
||||
|
||||
// Disabled: X(f1 & GF(f2)) = X(f1) & GF(f2)
|
||||
// Disabled: X(f1 | GF(f2)) = X(f1) | GF(f2)
|
||||
// Disabled: X(f1 & FG(f2)) = X(f1) & FG(f2)
|
||||
|
|
@ -914,11 +1046,9 @@ namespace spot
|
|||
if (opt_.event_univ && result_->is_eventual())
|
||||
return;
|
||||
|
||||
if (!opt_.reduce_basics)
|
||||
break;
|
||||
|
||||
// F(a U b) = F(b)
|
||||
if (opt_.reduce_basics)
|
||||
{
|
||||
// F(a U b) = F(b)
|
||||
binop* bo = is_U(result_);
|
||||
if (bo)
|
||||
{
|
||||
|
|
@ -928,7 +1058,6 @@ namespace spot
|
|||
result_ = recurse_destroy(r);
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
// FX(a) = XF(a)
|
||||
{
|
||||
|
|
@ -944,6 +1073,12 @@ namespace spot
|
|||
return;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// if Fa => a, keep a.
|
||||
if (opt_.containment_checks_stronger
|
||||
&& c_->lcc.contained(uo, result_))
|
||||
return;
|
||||
|
||||
// Disabled: F(f1 & GF(f2)) = F(f1) & GF(f2)
|
||||
//
|
||||
|
|
@ -972,8 +1107,8 @@ namespace spot
|
|||
if (opt_.event_univ && result_->is_universal())
|
||||
return;
|
||||
|
||||
if (!opt_.reduce_basics)
|
||||
break;
|
||||
if (opt_.reduce_basics)
|
||||
{
|
||||
|
||||
// G(a R b) = G(b)
|
||||
if (result_->kind() == formula::BinOp)
|
||||
|
|
@ -1013,22 +1148,38 @@ namespace spot
|
|||
multop* mo = static_cast<multop*>(result_);
|
||||
if (mo->op() == multop::Or)
|
||||
{
|
||||
mo->clone();
|
||||
mospliter s(mospliter::Strip_GF |
|
||||
mospliter::Split_EventUniv,
|
||||
mo, c_);
|
||||
s.res_EventUniv->push_back(unop_multop(unop::G,
|
||||
multop::Or,
|
||||
s.res_EventUniv->
|
||||
push_back(unop_multop(unop::G, multop::Or,
|
||||
s.res_other));
|
||||
s.res_EventUniv->push_back(unop_unop_multop(unop::G,
|
||||
unop::F,
|
||||
multop::Or,
|
||||
s.res_GF));
|
||||
result_ = multop::instance(multop::Or, s.res_EventUniv);
|
||||
s.res_EventUniv->
|
||||
push_back(unop_unop_multop(unop::G, unop::F,
|
||||
multop::Or, s.res_GF));
|
||||
result_ = multop::instance(multop::Or,
|
||||
s.res_EventUniv);
|
||||
if (result_ != uo)
|
||||
{
|
||||
mo->destroy();
|
||||
result_ = recurse_destroy(result_);
|
||||
return;
|
||||
}
|
||||
else
|
||||
{
|
||||
// Revert to the previous value of result_,
|
||||
// for the next simplification.
|
||||
result_->destroy();
|
||||
result_ = mo;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
// if a => Ga, keep a.
|
||||
if (opt_.containment_checks_stronger
|
||||
&& c_->lcc.contained(result_, uo))
|
||||
return;
|
||||
break;
|
||||
case unop::Finish:
|
||||
case unop::Closure:
|
||||
|
|
@ -1044,50 +1195,51 @@ namespace spot
|
|||
{
|
||||
binop::type op = bo->op();
|
||||
|
||||
formula* f2 = recurse(bo->second());
|
||||
formula* b = recurse(bo->second());
|
||||
|
||||
if (opt_.event_univ)
|
||||
{
|
||||
/* If b is a pure eventuality formula then a U b = b.
|
||||
If b is a pure universality formula a R b = b. */
|
||||
if ((f2->is_eventual() && (op == binop::U))
|
||||
|| (f2->is_universal() && (op == binop::R)))
|
||||
if ((b->is_eventual() && (op == binop::U))
|
||||
|| (b->is_universal() && (op == binop::R)))
|
||||
{
|
||||
result_ = f2;
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
formula* f1 = recurse(bo->first());
|
||||
formula* a = recurse(bo->first());
|
||||
|
||||
if (opt_.event_univ)
|
||||
{
|
||||
/* If a is a pure eventuality formula then a M b = a & b.
|
||||
If a is a pure universality formula a W b = a|b. */
|
||||
if (f1->is_eventual() && (op == binop::M))
|
||||
if (a->is_eventual() && (op == binop::M))
|
||||
{
|
||||
formula* tmp = multop::instance(multop::And, f1, f2);
|
||||
formula* tmp = multop::instance(multop::And, a, b);
|
||||
result_ = recurse(tmp);
|
||||
tmp->destroy();
|
||||
return;
|
||||
}
|
||||
if (f1->is_universal() && (op == binop::W))
|
||||
if (a->is_universal() && (op == binop::W))
|
||||
{
|
||||
formula* tmp = multop::instance(multop::Or, f1, f2);
|
||||
formula* tmp = multop::instance(multop::Or, a, b);
|
||||
result_ = recurse(tmp);
|
||||
tmp->destroy();
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
/* case of implies */
|
||||
if (opt_.synt_impl)
|
||||
// Inclusion-based rules
|
||||
if (opt_.synt_impl | opt_.containment_checks)
|
||||
{
|
||||
switch (op)
|
||||
{
|
||||
case binop::Xor:
|
||||
case binop::Equiv:
|
||||
case binop::Implies:
|
||||
assert(!"operator not supported for syntactic implication");
|
||||
assert(!"operator not supported for implication rules");
|
||||
return;
|
||||
case binop::UConcat:
|
||||
case binop::EConcat:
|
||||
|
|
@ -1095,141 +1247,150 @@ namespace spot
|
|||
break;
|
||||
|
||||
case binop::U:
|
||||
/* a < b => a U b = b */
|
||||
if (c_->syntactic_implication(f1, f2))
|
||||
// if a => b, then a U b = b
|
||||
// if (a U b) => b, then a U b = b (for stronger containment)
|
||||
if (c_->implication(a, b)
|
||||
|| (opt_.containment_checks_stronger
|
||||
&& c_->contained(bo, b)))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
/* !b < a => a U b = Fb */
|
||||
if (c_->syntactic_implication_neg(f2, f1, false))
|
||||
// if !a => b, then a U b = Fb
|
||||
if (c_->implication_neg(a, b, false))
|
||||
{
|
||||
result_ = unop::instance(unop::F, f2);
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ =
|
||||
recurse_destroy(unop::instance(unop::F, b));
|
||||
return;
|
||||
}
|
||||
/* a < b => a U (b U c) = (b U c) */
|
||||
/* a < b => a U (b W c) = (b W c) */
|
||||
if (f2->kind() == formula::BinOp)
|
||||
// if a => b, then a U (b U c) = (b U c)
|
||||
// if a => b, then a U (b W c) = (b W c)
|
||||
if (b->kind() == formula::BinOp)
|
||||
{
|
||||
binop* bo = static_cast<binop*>(f2);
|
||||
binop* bo = static_cast<binop*>(b);
|
||||
if ((bo->op() == binop::U || bo->op() == binop::W)
|
||||
&& c_->syntactic_implication(f1, bo->first()))
|
||||
&& c_->implication(a, bo->first()))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case binop::R:
|
||||
/* b < a => a R b = b */
|
||||
if (c_->syntactic_implication(f2, f1))
|
||||
// if b => a, then a R b = b
|
||||
if (c_->implication(b, a))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
/* b < !a => a R b = Gb */
|
||||
if (c_->syntactic_implication_neg(f2, f1, true))
|
||||
// if b => !a, then a R b = Gb
|
||||
if (c_->implication_neg(b, a, true))
|
||||
{
|
||||
result_ = unop::instance(unop::G, f2);
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ = unop::instance(unop::G, b);
|
||||
return;
|
||||
}
|
||||
if (f2->kind() == formula::BinOp)
|
||||
if (b->kind() == formula::BinOp)
|
||||
{
|
||||
/* b < a => a R (b R c) = b R c */
|
||||
/* b < a => a R (b M c) = b M c */
|
||||
binop* bo = static_cast<binop*>(f2);
|
||||
// if b => a, then a R (b R c) = b R c
|
||||
// if b => a, then a R (b M c) = b M c
|
||||
binop* bo = static_cast<binop*>(b);
|
||||
if ((bo->op() == binop::R || bo->op() == binop::M)
|
||||
&& c_->syntactic_implication(bo->first(), f1))
|
||||
&& c_->implication(bo->first(), a))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
|
||||
/* a < b => a R (b R c) = a R c */
|
||||
// if a => b, then a R (b R c) = a R c
|
||||
if (bo->op() == binop::R
|
||||
&& c_->syntactic_implication(f1, bo->first()))
|
||||
&& c_->implication(a, bo->first()))
|
||||
{
|
||||
result_ = binop::instance(binop::R, f1,
|
||||
bo->second()->clone());
|
||||
f2->destroy();
|
||||
b->destroy();
|
||||
result_ = recurse_destroy
|
||||
(binop::instance(binop::R, a,
|
||||
bo->second()->clone()));
|
||||
return;
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case binop::W:
|
||||
/* a < b => a W b = b */
|
||||
if (c_->syntactic_implication(f1, f2))
|
||||
// if a => b, then a W b = b
|
||||
// if a W b => b, then a W b = b (for stronger containment)
|
||||
if (c_->implication(a, b)
|
||||
|| (opt_.containment_checks_stronger
|
||||
&& c_->contained(bo, b)))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
/* !b < a => a W b = 1 */
|
||||
if (c_->syntactic_implication_neg(f2, f1, false))
|
||||
// if !a => b then a W b = 1
|
||||
if (c_->implication_neg(a, b, false))
|
||||
{
|
||||
a->destroy();
|
||||
b->destroy();
|
||||
result_ = constant::true_instance();
|
||||
f1->destroy();
|
||||
f2->destroy();
|
||||
return;
|
||||
}
|
||||
/* a < b => a W (b W c) = (b W c) */
|
||||
if (f2->kind() == formula::BinOp)
|
||||
// if a => b, then a W (b W c) = (b W c)
|
||||
if (b->kind() == formula::BinOp)
|
||||
{
|
||||
binop* bo = static_cast<binop*>(f2);
|
||||
binop* bo = static_cast<binop*>(b);
|
||||
if (bo->op() == binop::W
|
||||
&& c_->syntactic_implication(f1, bo->first()))
|
||||
&& c_->implication(a, bo->first()))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case binop::M:
|
||||
/* b < a => a M b = b */
|
||||
if (c_->syntactic_implication(f2, f1))
|
||||
// if b => a, then a M b = b
|
||||
if (c_->implication(b, a))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
/* b < !a => a M b = 0 */
|
||||
if (c_->syntactic_implication_neg(f2, f1, true))
|
||||
// if b => !a, then a M b = 0
|
||||
if (c_->implication_neg(b, a, true))
|
||||
{
|
||||
a->destroy();
|
||||
b->destroy();
|
||||
result_ = constant::false_instance();
|
||||
f1->destroy();
|
||||
f2->destroy();
|
||||
return;
|
||||
}
|
||||
if (f2->kind() == formula::BinOp)
|
||||
if (b->kind() == formula::BinOp)
|
||||
{
|
||||
/* b < a => a M (b M c) = b M c */
|
||||
binop* bo = static_cast<binop*>(f2);
|
||||
// if b => a, then a M (b M c) = b M c
|
||||
binop* bo = static_cast<binop*>(b);
|
||||
if (bo->op() == binop::M
|
||||
&& c_->syntactic_implication(bo->first(), f1))
|
||||
&& c_->implication(bo->first(), a))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
result_ = b;
|
||||
a->destroy();
|
||||
return;
|
||||
}
|
||||
|
||||
/* a < b => a M (b M c) = a M c */
|
||||
/* a < b => a M (b R c) = a M c */
|
||||
// if a => b, then a M (b M c) = a M c
|
||||
// if a => b, then a M (b R c) = a M c
|
||||
if ((bo->op() == binop::M || bo->op() == binop::R)
|
||||
&& c_->syntactic_implication(f1, bo->first()))
|
||||
&& c_->implication(a, bo->first()))
|
||||
{
|
||||
result_ = binop::instance(binop::M, f1,
|
||||
bo->second()->clone());
|
||||
f2->destroy();
|
||||
b->destroy();
|
||||
result_ = recurse_destroy
|
||||
(binop::instance(binop::M, a,
|
||||
bo->second()->clone()));
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
|
@ -1237,39 +1398,44 @@ namespace spot
|
|||
}
|
||||
}
|
||||
|
||||
if (!opt_.reduce_basics)
|
||||
{
|
||||
result_ = binop::instance(op, a, b);
|
||||
return;
|
||||
}
|
||||
|
||||
// Rewrite U,R,W,M as F or G when possible.
|
||||
switch (op)
|
||||
{
|
||||
case binop::U:
|
||||
// true U f2 == F(f2)
|
||||
if (f1 == constant::true_instance())
|
||||
// true U b == F(b)
|
||||
if (a == constant::true_instance())
|
||||
{
|
||||
result_ = recurse_destroy(unop::instance(unop::F, f2));
|
||||
result_ = recurse_destroy(unop::instance(unop::F, b));
|
||||
return;
|
||||
}
|
||||
break;
|
||||
case binop::R:
|
||||
// false R f2 == G(f2)
|
||||
if (f1 == constant::false_instance())
|
||||
// false R b == G(b)
|
||||
if (a == constant::false_instance())
|
||||
{
|
||||
result_ = recurse_destroy(unop::instance(unop::G, f2));
|
||||
result_ = recurse_destroy(unop::instance(unop::G, b));
|
||||
return;
|
||||
}
|
||||
break;
|
||||
case binop::W:
|
||||
// f1 W false == G(f1)
|
||||
if (f2 == constant::false_instance())
|
||||
// a W false == G(a)
|
||||
if (b == constant::false_instance())
|
||||
{
|
||||
result_ = recurse_destroy(unop::instance(unop::G, f1));
|
||||
result_ = recurse_destroy(unop::instance(unop::G, a));
|
||||
return;
|
||||
}
|
||||
break;
|
||||
case binop::M:
|
||||
// f1 M true == F(f1)
|
||||
if (f2 == constant::false_instance())
|
||||
// a M true == F(a)
|
||||
if (b == constant::false_instance())
|
||||
{
|
||||
result_ = recurse_destroy(unop::instance(unop::F, f1));
|
||||
result_ = recurse_destroy(unop::instance(unop::F, a));
|
||||
return;
|
||||
}
|
||||
break;
|
||||
|
|
@ -1291,18 +1457,18 @@ namespace spot
|
|||
// a R true = true
|
||||
// a W true = true
|
||||
// a M false = false
|
||||
if (is_constant(f2))
|
||||
if (is_constant(b))
|
||||
{
|
||||
result_ = f2;
|
||||
f1->destroy();
|
||||
result_ = b;
|
||||
a->destroy();
|
||||
return;
|
||||
}
|
||||
|
||||
// Same effect as dynamic_cast<unop*>, only faster.
|
||||
unop* fu1 =
|
||||
(f1->kind() == formula::UnOp) ? static_cast<unop*>(f1) : 0;
|
||||
(a->kind() == formula::UnOp) ? static_cast<unop*>(a) : 0;
|
||||
unop* fu2 =
|
||||
(f2->kind() == formula::UnOp) ? static_cast<unop*>(f2) : 0;
|
||||
(b->kind() == formula::UnOp) ? static_cast<unop*>(b) : 0;
|
||||
|
||||
// X(a) U X(b) = X(a U b)
|
||||
// X(a) R X(b) = X(a R b)
|
||||
|
|
@ -1315,8 +1481,8 @@ namespace spot
|
|||
formula* bin = binop::instance(op,
|
||||
fu1->child()->clone(),
|
||||
fu2->child()->clone());
|
||||
f1->destroy();
|
||||
f2->destroy();
|
||||
a->destroy();
|
||||
b->destroy();
|
||||
result_ = recurse_destroy(unop::instance(unop::X, bin));
|
||||
return;
|
||||
}
|
||||
|
|
@ -1325,18 +1491,18 @@ namespace spot
|
|||
{
|
||||
// a U Ga = Ga
|
||||
// a W Ga = Ga
|
||||
if (fu2 && fu2->op() == unop::G && fu2->child() == f1)
|
||||
if (fu2 && fu2->op() == unop::G && fu2->child() == a)
|
||||
{
|
||||
f1->destroy();
|
||||
result_ = f2;
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
|
||||
// a U (b | c | G(a)) = a W (b | c)
|
||||
// a W (b | c | G(a)) = a W (b | c)
|
||||
if (f2->kind() == formula::MultOp)
|
||||
if (b->kind() == formula::MultOp)
|
||||
{
|
||||
multop* fm2 = static_cast<multop*>(f2);
|
||||
multop* fm2 = static_cast<multop*>(b);
|
||||
if (fm2->op() == multop::Or)
|
||||
{
|
||||
int s = fm2->size();
|
||||
|
|
@ -1345,7 +1511,7 @@ namespace spot
|
|||
if (fm2->nth(i)->kind() != formula::UnOp)
|
||||
continue;
|
||||
unop* c = static_cast<unop*>(fm2->nth(i));
|
||||
if (c->op() == unop::G && c->child() == f1)
|
||||
if (c->op() == unop::G && c->child() == a)
|
||||
{
|
||||
multop::vec* v = new multop::vec;
|
||||
v->reserve(s - 1);
|
||||
|
|
@ -1355,9 +1521,9 @@ namespace spot
|
|||
// skip j=i
|
||||
for (++j; j < s; ++j)
|
||||
v->push_back(fm2->nth(j)->clone());
|
||||
f2->destroy();
|
||||
b->destroy();
|
||||
result_ = recurse_destroy(binop::instance
|
||||
(binop::W, f1,
|
||||
(binop::W, a,
|
||||
multop::instance(multop::Or, v)));
|
||||
return;
|
||||
}
|
||||
|
|
@ -1369,18 +1535,18 @@ namespace spot
|
|||
{
|
||||
// a R Fa = Fa
|
||||
// a M Fa = Fa
|
||||
if (fu2 && fu2->op() == unop::F && fu2->child() == f1)
|
||||
if (fu2 && fu2->op() == unop::F && fu2->child() == a)
|
||||
{
|
||||
f1->destroy();
|
||||
result_ = f2;
|
||||
a->destroy();
|
||||
result_ = b;
|
||||
return;
|
||||
}
|
||||
|
||||
// a R (b & c & F(a)) = a M b
|
||||
// a M (b & c & F(a)) = a M b
|
||||
if (f2->kind() == formula::MultOp)
|
||||
if (b->kind() == formula::MultOp)
|
||||
{
|
||||
multop* fm2 = static_cast<multop*>(f2);
|
||||
multop* fm2 = static_cast<multop*>(b);
|
||||
if (fm2->op() == multop::And)
|
||||
{
|
||||
int s = fm2->size();
|
||||
|
|
@ -1389,7 +1555,7 @@ namespace spot
|
|||
if (fm2->nth(i)->kind() != formula::UnOp)
|
||||
continue;
|
||||
unop* c = static_cast<unop*>(fm2->nth(i));
|
||||
if (c->op() == unop::F && c->child() == f1)
|
||||
if (c->op() == unop::F && c->child() == a)
|
||||
{
|
||||
multop::vec* v = new multop::vec;
|
||||
v->reserve(s - 1);
|
||||
|
|
@ -1399,9 +1565,9 @@ namespace spot
|
|||
// skip j=i
|
||||
for (++j; j < s; ++j)
|
||||
v->push_back(fm2->nth(j)->clone());
|
||||
f2->destroy();
|
||||
b->destroy();
|
||||
result_ = recurse_destroy(binop::instance
|
||||
(binop::M, f1,
|
||||
(binop::M, a,
|
||||
multop::instance(multop::And, v)));
|
||||
return;
|
||||
}
|
||||
|
|
@ -1416,11 +1582,11 @@ namespace spot
|
|||
case binop::EConcat:
|
||||
case binop::UConcat:
|
||||
case binop::EConcatMarked:
|
||||
// No simplification.
|
||||
// No simplification... Yet?
|
||||
break;
|
||||
}
|
||||
|
||||
result_ = binop::instance(op, f1, f2);
|
||||
result_ = binop::instance(op, a, b);
|
||||
}
|
||||
|
||||
void
|
||||
|
|
@ -1440,77 +1606,74 @@ namespace spot
|
|||
|
||||
multop::type op = mo->op();
|
||||
|
||||
if ((opt_.synt_impl)
|
||||
if ((opt_.synt_impl | opt_.containment_checks)
|
||||
&& (op != multop::Concat)
|
||||
&& (op != multop::Fusion))
|
||||
{
|
||||
bool is_and = op != multop::Or; // And or AndNLM
|
||||
constant* neutral = is_and
|
||||
? constant::false_instance() : constant::true_instance();
|
||||
|
||||
bool removed = true;
|
||||
multop::vec::iterator f1;
|
||||
multop::vec::iterator f2;
|
||||
multop::vec::iterator f1 = res->begin();
|
||||
|
||||
while (removed)
|
||||
{
|
||||
removed = false;
|
||||
f2 = f1 = res->begin();
|
||||
++f1;
|
||||
while (f1 != res->end())
|
||||
{
|
||||
assert(f1 != f2);
|
||||
// a < b => a + b = b
|
||||
// a < b => a & b = a
|
||||
if ((c_->syntactic_implication(*f1, *f2) && // f1 < f2
|
||||
(mo->op() == multop::Or)) ||
|
||||
((c_->syntactic_implication(*f2, *f1)) && // f2 < f1
|
||||
(mo->op() == multop::And)))
|
||||
multop::vec::iterator f2 = f1;
|
||||
++f2
|
||||
;
|
||||
while (f2 != res->end())
|
||||
{
|
||||
// We keep f2
|
||||
assert(f1 != f2);
|
||||
// if f1 => f2, then f1 | f2 = f2
|
||||
// if f2 => f1, then f1 & f2 = f2
|
||||
if ((op == multop::Or && c_->implication(*f1, *f2))
|
||||
|| (op == multop::And && c_->implication(*f2, *f1)))
|
||||
{
|
||||
// Remove f1.
|
||||
(*f1)->destroy();
|
||||
res->erase(f1);
|
||||
removed = true;
|
||||
*f1 = 0;
|
||||
++f1;
|
||||
break;
|
||||
}
|
||||
else if ((c_->syntactic_implication(*f2, *f1) // f2 < f1
|
||||
&& (mo->op() == multop::Or)) ||
|
||||
((c_->syntactic_implication(*f1, *f2)) // f1 < f2
|
||||
&& (mo->op() == multop::And)))
|
||||
// if f2 => f1, then f1 | f2 = f1
|
||||
// if f1 => f2, then f1 & f2 = f1
|
||||
else if ((op == multop::Or && c_->implication(*f2, *f1))
|
||||
|| (op == multop::And
|
||||
&& c_->implication(*f1, *f2)))
|
||||
{
|
||||
// We keep f1
|
||||
// Remove f2.
|
||||
(*f2)->destroy();
|
||||
res->erase(f2);
|
||||
removed = true;
|
||||
break;
|
||||
// replace it by the last element from the array.
|
||||
// and start again at the current position.
|
||||
if (f2 != --res->end())
|
||||
{
|
||||
*f2 = res->back();
|
||||
res->pop_back();
|
||||
continue;
|
||||
}
|
||||
else
|
||||
++f1;
|
||||
}
|
||||
}
|
||||
|
||||
// We cannot run syntactic_implication_neg on SERE
|
||||
// formulae, unless they are just Boolean formulae.
|
||||
if (mo->is_boolean() || !mo->is_sere_formula())
|
||||
{
|
||||
bool is_and = mo->op() != multop::Or;
|
||||
/* f1 < !f2 => f1 & f2 = false
|
||||
!f1 < f2 => f1 | f2 = true */
|
||||
for (f1 = res->begin(); f1 != res->end(); f1++)
|
||||
for (f2 = res->begin(); f2 != res->end(); f2++)
|
||||
if (f1 != f2 &&
|
||||
c_->syntactic_implication_neg(*f1, *f2, is_and))
|
||||
res->pop_back();
|
||||
break;
|
||||
}
|
||||
}
|
||||
// if f1 => !f2, then f1 & f2 = false
|
||||
// if !f1 => f2, then f1 | f2 = true
|
||||
else if (c_->implication_neg(*f1, *f2, is_and))
|
||||
{
|
||||
for (multop::vec::iterator j = res->begin();
|
||||
j != res->end(); j++)
|
||||
if (*j)
|
||||
(*j)->destroy();
|
||||
res->clear();
|
||||
delete res;
|
||||
if (is_and)
|
||||
result_ = constant::false_instance();
|
||||
else
|
||||
result_ = constant::true_instance();
|
||||
result_ = neutral;
|
||||
return;
|
||||
}
|
||||
else
|
||||
++f2;
|
||||
}
|
||||
++f1;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
assert(!res->empty());
|
||||
|
|
@ -1521,7 +1684,7 @@ namespace spot
|
|||
{
|
||||
case multop::And:
|
||||
{
|
||||
// Gather all operand by type.
|
||||
// Gather all operands by type.
|
||||
mospliter s(mospliter::Strip_X |
|
||||
mospliter::Strip_FG |
|
||||
mospliter::Strip_G |
|
||||
|
|
|
|||
|
|
@ -31,15 +31,20 @@ namespace spot
|
|||
class ltl_simplifier_options
|
||||
{
|
||||
public:
|
||||
ltl_simplifier_options()
|
||||
: reduce_basics(true),
|
||||
synt_impl(true),
|
||||
event_univ(true),
|
||||
containment_checks(false),
|
||||
containment_checks_stronger(false),
|
||||
ltl_simplifier_options(bool basics = true,
|
||||
bool synt_impl = true,
|
||||
bool event_univ = true,
|
||||
bool containment_checks = false,
|
||||
bool containment_checks_stronger = false,
|
||||
bool nenoform_stop_on_boolean = false)
|
||||
: reduce_basics(basics),
|
||||
synt_impl(synt_impl),
|
||||
event_univ(event_univ),
|
||||
containment_checks(containment_checks),
|
||||
containment_checks_stronger(containment_checks_stronger),
|
||||
// If true, Boolean subformulae will not be put into
|
||||
// negative normal form.
|
||||
nenoform_stop_on_boolean(false)
|
||||
nenoform_stop_on_boolean(nenoform_stop_on_boolean)
|
||||
{
|
||||
}
|
||||
|
||||
|
|
@ -48,6 +53,8 @@ namespace spot
|
|||
bool event_univ;
|
||||
bool containment_checks;
|
||||
bool containment_checks_stronger;
|
||||
// If true, Boolean subformulae will not be put into
|
||||
// negative normal form.
|
||||
bool nenoform_stop_on_boolean;
|
||||
};
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue