/**
* Cluster conjuncts to produce a partitioned transition relation.
*
* Conjuncts larger than limit are rejected (unless they are
* singletons).
*/
vector<BDD> BddTrAttachment::clusterConjunctsOld(
vector<BDD>& conjuncts,
unsigned int limit,
Options::Verbosity verbosity,
int nvars) const
{
vector<BDD> clusters;
if (conjuncts.size() == 0) {
clusters.push_back(bddManager().bddOne());
return clusters;
}
vector<BDD>::const_reverse_iterator it = conjuncts.rbegin();
BDD cluster = *it++;
conjuncts.pop_back();
while (it != conjuncts.rend()) {
reportBDD("conjunct", *it, nvars, verbosity, Options::Informative);
BDD tmp = cluster.And(*it,limit);
if (tmp && (unsigned int) tmp.nodeCount() <= 2*limit) {
cluster = tmp;
} else {
reportBDD("Cluster", cluster, nvars, verbosity, Options::Informative);
clusters.push_back(cluster);
cluster = *it;
}
++it;
conjuncts.pop_back();
}
reportBDD("Cluster", cluster, nvars, verbosity, Options::Informative);
clusters.push_back(cluster);
return clusters;
} // BddTrAttachment::clusterConjunctsOld
BDD Synth::pre_sys(BDD dst) {
/**
Calculate predecessor states of given states.
∀u ∃c ∃t': tau(t,u,c,t') & dst(t') & ~error(t,u,c)
We use the direct substitution optimization (since t' <-> BDD(t,u,c)), thus:
∀u ∃c: (!error(t,u,c) & (dst(t)[t <- bdd_next_t(t,u,c)]))
or for Moore machines:
∃c ∀u: (!error(t,u,c) & (dst(t)[t <- bdd_next_t(t,u,c)]))
Note that we do not replace t variables in the error bdd.
:return: BDD of the predecessor states
**/
// NOTE: I tried considering two special cases: error(t,u,c) and error(t),
// and move error(t) outside of quantification ∀u ∃c.
// It slowed down..
// TODO: try again: on the driver example
static vector<VecUint> orders;
static bool did_grouping = false;
if (!did_grouping && timer.sec_from_origin() > time_limit_sec/4) { // at 0.25*time_limit we fix the order
do_grouping(cudd, orders);
did_grouping = true;
}
dst = dst.VectorCompose(get_substitution()); update_order_if(cudd, orders);
if (is_moore) {
BDD result = dst.And(~error);
vector<BDD> uncontrollable = get_uncontrollable_vars_bdds();
if (!uncontrollable.empty()) {
BDD uncontrollable_cube = cudd.bddComputeCube(uncontrollable.data(),
NULL,
(int)uncontrollable.size());
result = result.UnivAbstract(uncontrollable_cube); update_order_if(cudd, orders);
}
// ∃c ∀u (...)
vector<BDD> controllable = get_controllable_vars_bdds();
BDD controllable_cube = cudd.bddComputeCube(controllable.data(),
NULL,
(int)controllable.size());
result = result.ExistAbstract(controllable_cube); update_order_if(cudd, orders);
return result;
}
// the case of Mealy machines
vector<BDD> controllable = get_controllable_vars_bdds();
BDD controllable_cube = cudd.bddComputeCube(controllable.data(),
NULL,
(int)controllable.size());
BDD result = dst.AndAbstract(~error, controllable_cube); update_order_if(cudd, orders);
vector<BDD> uncontrollable = get_uncontrollable_vars_bdds();
if (!uncontrollable.empty()) {
// ∀u ∃c (...)
BDD uncontrollable_cube = cudd.bddComputeCube(uncontrollable.data(),
NULL,
(int)uncontrollable.size());
result = result.UnivAbstract(uncontrollable_cube); update_order_if(cudd, orders);
}
return result;
}