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/********************* */
/*! \file sygus_unif_rl.cpp
** \verbatim
** Top contributors (to current version):
** Haniel Barbosa
** This file is part of the CVC4 project.
** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS
** in the top-level source directory) and their institutional affiliations.
** All rights reserved. See the file COPYING in the top-level source
** directory for licensing information.\endverbatim
**
** \brief Implementation of sygus_unif_rl
**/
#include "theory/quantifiers/sygus/sygus_unif_rl.h"
#include "theory/quantifiers/sygus/ce_guided_conjecture.h"
#include "theory/quantifiers/sygus/term_database_sygus.h"
using namespace CVC4::kind;
namespace CVC4 {
namespace theory {
namespace quantifiers {
SygusUnifRl::SygusUnifRl(CegConjecture* p) : d_parent(p) {}
SygusUnifRl::~SygusUnifRl() {}
void SygusUnifRl::initialize(QuantifiersEngine* qe,
const std::vector<Node>& funs,
std::vector<Node>& enums,
std::vector<Node>& lemmas)
{
d_ecache.clear();
d_cand_to_cond_enum.clear();
d_cand_to_pt_enum.clear();
/* TODO populate d_unif_candidates and remove lemmas cleaning */
SygusUnif::initialize(qe, funs, enums, lemmas);
lemmas.clear();
/* Copy candidates and check whether CegisUnif for any of them */
for (const Node& c : d_unif_candidates)
{
d_app_to_pt[c].clear();
d_cand_to_pt_enum[c].clear();
d_purified_count[c] = 0;
}
}
void SygusUnifRl::notifyEnumeration(Node e, Node v, std::vector<Node>& lemmas)
{
Trace("sygus-unif-rl-notify") << "SyGuSUnifRl: Adding to enum " << e
<< " value " << v << "\n";
d_ecache[e].d_enum_vals.push_back(v);
/* Exclude v from next enumerations for e */
Node exc_lemma =
d_tds->getExplain()->getExplanationForEquality(e, v).negate();
Trace("sygus-unif-rl-notify")
<< "SygusUnifRl : enumeration exclude lemma : " << exc_lemma << std::endl;
lemmas.push_back(exc_lemma);
}
Node SygusUnifRl::purifyLemma(Node n,
bool ensureConst,
std::vector<Node>& model_guards,
BoolNodePairMap& cache)
{
Trace("sygus-unif-rl-purify") << "PurifyLemma : " << n << "\n";
BoolNodePairMap::const_iterator it = cache.find(BoolNodePair(ensureConst, n));
if (it != cache.end())
{
Trace("sygus-unif-rl-purify-debug") << "... already visited " << n << "\n";
return it->second;
}
/* Recurse */
unsigned size = n.getNumChildren();
Kind k = n.getKind();
/* Whether application of a function-to-synthesize */
bool fapp = k == APPLY_UF && size > 0;
Assert(std::find(d_candidates.begin(), d_candidates.end(), n[0])
== d_candidates.end());
/* Whether application of a (non-)unification function-to-synthesize */
bool u_fapp = fapp && usingUnif(n[0]);
bool nu_fapp = fapp && !usingUnif(n[0]);
/* We retrive model value now because purified node may not have a value */
Node nv = n;
/* get model value of non-top level applications of functions-to-synthesize
occurring under a unification function-to-synthesize */
if (ensureConst && fapp)
{
nv = d_parent->getModelValue(n);
Assert(n != nv);
Trace("sygus-unif-rl-purify") << "PurifyLemma : model value for " << n
<< " is " << nv << "\n";
}
/* Travese to purify */
bool childChanged = false;
std::vector<Node> children;
NodeManager* nm = NodeManager::currentNM();
for (unsigned i = 0; i < size; ++i)
{
if (i == 0 && fapp)
{
children.push_back(n[i]);
continue;
}
/* Arguments of non-unif functions do not need to be constant */
Node child = purifyLemma(
n[i], !nu_fapp && (ensureConst || u_fapp), model_guards, cache);
children.push_back(child);
childChanged = childChanged || child != n[i];
}
Node nb;
if (childChanged)
{
if (n.hasOperator())
{
children.insert(children.begin(), n.getOperator());
}
nb = NodeManager::currentNM()->mkNode(k, children);
Trace("sygus-unif-rl-purify") << "PurifyLemma : transformed " << n
<< " into " << nb << "\n";
}
else
{
nb = n;
}
/* Map to point enumerator every unification function-to-synthesize */
if (u_fapp)
{
Node np;
std::map<Node, Node>::const_iterator it = d_app_to_purified.find(nb);
if (it == d_app_to_purified.end())
{
if (!childChanged)
{
Assert(nb.hasOperator());
children.insert(children.begin(), n.getOperator());
}
/* Build purified head with fresh skolem and recreate node */
std::stringstream ss;
ss << nb[0] << "_" << d_purified_count[nb[0]]++;
Node new_f = nm->mkSkolem(ss.str(), nb[0].getType());
/* Adds new enumerator to map from candidate */
Trace("sygus-unif-rl-purify") << "...new enum " << new_f
<< " for candidate " << nb[0] << "\n";
d_cand_to_pt_enum[nb[0]].push_back(new_f);
/* Maps new enumerator to its respective tuple of arguments */
d_app_to_pt[new_f] =
std::vector<Node>(children.begin() + 2, children.end());
if (Trace.isOn("sygus-unif-rl-purify"))
{
Trace("sygus-unif-rl-purify") << "...[" << new_f << "] --> (";
for (const Node& pt_i : d_app_to_pt[new_f])
{
Trace("sygus-unif-rl-purify") << pt_i << " ";
}
Trace("sygus-unif-rl-purify") << ")\n";
}
/* replace first child and rebulid node */
children[1] = new_f;
np = NodeManager::currentNM()->mkNode(k, children);
d_app_to_purified[nb] = np;
}
else
{
np = it->second;
}
Trace("sygus-unif-rl-purify")
<< "PurifyLemma : purified head and transformed " << nb << " into "
<< np << "\n";
nb = np;
}
/* Add equality between purified fapp and model value */
if (ensureConst && fapp)
{
model_guards.push_back(
NodeManager::currentNM()->mkNode(EQUAL, nv, nb).negate());
nb = nv;
Trace("sygus-unif-rl-purify") << "PurifyLemma : adding model eq "
<< model_guards.back() << "\n";
}
nb = Rewriter::rewrite(nb);
/* every non-top level application of function-to-synthesize must be reduced
to a concrete constant */
Assert(!ensureConst || nb.isConst());
Trace("sygus-unif-rl-purify-debug") << "... caching [" << n << "] = " << nb
<< "\n";
cache[BoolNodePair(ensureConst, n)] = nb;
return nb;
}
Node SygusUnifRl::addRefLemma(Node lemma)
{
Trace("sygus-unif-rl-purify") << "Registering lemma at SygusUnif : " << lemma
<< "\n";
std::vector<Node> model_guards;
BoolNodePairMap cache;
/* Make the purified lemma which will guide the unification utility. */
Node plem = purifyLemma(lemma, false, model_guards, cache);
if (!model_guards.empty())
{
model_guards.push_back(plem);
plem = NodeManager::currentNM()->mkNode(OR, model_guards);
}
plem = Rewriter::rewrite(plem);
Trace("sygus-unif-rl-purify") << "Purified lemma : " << plem << "\n";
return plem;
}
void SygusUnifRl::initializeConstructSol() {}
void SygusUnifRl::initializeConstructSolFor(Node f) {}
bool SygusUnifRl::constructSolution(std::vector<Node>& sols)
{
for (const Node& c : d_candidates)
{
if (!usingUnif(c))
{
Node v = d_parent->getModelValue(c);
Trace("sygus-unif-rl-sol") << "Adding solution " << v
<< " to non-unif candidate " << c << "\n";
sols.push_back(v);
}
else
{
return false;
}
}
return true;
}
Node SygusUnifRl::constructSol(Node f, Node e, NodeRole nrole, int ind)
{
return Node::null();
}
bool SygusUnifRl::usingUnif(Node f)
{
return d_unif_candidates.find(f) != d_unif_candidates.end();
}
} /* CVC4::theory::quantifiers namespace */
} /* CVC4::theory namespace */
} /* CVC4 namespace */
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