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/********************* */
/*! \file template_infer.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Mathias Preiner
** This file is part of the CVC4 project.
** Copyright (c) 2009-2020 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 utility for processing single invocation synthesis conjectures
**
**/
#include "theory/quantifiers/sygus/template_infer.h"
#include "options/quantifiers_options.h"
#include "theory/quantifiers/sygus/sygus_grammar_cons.h"
#include "theory/quantifiers/sygus/sygus_utils.h"
#include "theory/quantifiers/term_util.h"
using namespace CVC4::kind;
namespace CVC4 {
namespace theory {
namespace quantifiers {
void SygusTemplateInfer::initialize(Node q)
{
Assert(d_quant.isNull());
Assert(q.getKind() == FORALL);
d_quant = q;
// We are processing without single invocation techniques, now check if
// we should fix an invariant template (post-condition strengthening or
// pre-condition weakening).
options::SygusInvTemplMode tmode = options::sygusInvTemplMode();
if (tmode != options::SygusInvTemplMode::NONE)
{
// currently only works for single predicate synthesis
if (q[0].getNumChildren() > 1 || !q[0][0].getType().isPredicate())
{
tmode = options::SygusInvTemplMode::NONE;
}
else if (!options::sygusInvTemplWhenSyntax())
{
// only use invariant templates if no syntactic restrictions
if (CegGrammarConstructor::hasSyntaxRestrictions(q))
{
tmode = options::SygusInvTemplMode::NONE;
}
}
}
if (tmode == options::SygusInvTemplMode::NONE)
{
// not processing invariant templates
return;
}
Node qq;
if (q[1].getKind() == NOT && q[1][0].getKind() == FORALL)
{
qq = q[1][0][1];
}
else
{
qq = TermUtil::simpleNegate(q[1]);
}
if (qq.isConst())
{
// trivial, do not use transition inference
return;
}
// if we are doing invariant templates, then construct the template
Trace("sygus-si") << "- Do transition inference..." << std::endl;
d_ti.process(qq, q[0][0]);
Trace("cegqi-inv") << std::endl;
Node prog = d_ti.getFunction();
if (!d_ti.isComplete())
{
// the invariant could not be inferred
return;
}
Assert(prog == q[0][0]);
NodeManager* nm = NodeManager::currentNM();
// map the program back via non-single invocation map
std::vector<Node> prog_templ_vars;
d_ti.getVariables(prog_templ_vars);
d_trans_pre[prog] = d_ti.getPreCondition();
d_trans_post[prog] = d_ti.getPostCondition();
Trace("cegqi-inv") << " precondition : " << d_trans_pre[prog] << std::endl;
Trace("cegqi-inv") << " postcondition : " << d_trans_post[prog] << std::endl;
// construct template argument
TypeNode atn = prog.getType();
if (atn.isFunction())
{
atn = atn.getRangeType();
}
d_templ_arg[prog] = nm->mkSkolem("I", atn);
// construct template
Node templ;
if (options::sygusInvAutoUnfold())
{
if (d_ti.isComplete())
{
Trace("cegqi-inv-auto-unfold")
<< "Automatic deterministic unfolding... " << std::endl;
// auto-unfold
DetTrace dt;
int init_dt = d_ti.initializeTrace(dt);
if (init_dt == 0)
{
Trace("cegqi-inv-auto-unfold") << " Init : ";
dt.print("cegqi-inv-auto-unfold");
Trace("cegqi-inv-auto-unfold") << std::endl;
unsigned counter = 0;
unsigned status = 0;
while (counter < 100 && status == 0)
{
status = d_ti.incrementTrace(dt);
counter++;
Trace("cegqi-inv-auto-unfold") << " #" << counter << " : ";
dt.print("cegqi-inv-auto-unfold");
Trace("cegqi-inv-auto-unfold")
<< "...status = " << status << std::endl;
}
if (status == 1)
{
// we have a trivial invariant
templ = d_ti.constructFormulaTrace(dt);
Trace("cegqi-inv") << "By finite deterministic terminating trace, a "
"solution invariant is : "
<< std::endl;
Trace("cegqi-inv") << " " << templ << std::endl;
// this should be unnecessary
templ = nm->mkNode(AND, templ, d_templ_arg[prog]);
}
}
else
{
Trace("cegqi-inv-auto-unfold") << "...failed initialize." << std::endl;
}
}
}
Trace("cegqi-inv") << "Make the template... " << tmode << " " << templ
<< std::endl;
if (templ.isNull())
{
if (tmode == options::SygusInvTemplMode::PRE)
{
templ = nm->mkNode(OR, d_trans_pre[prog], d_templ_arg[prog]);
}
else
{
Assert(tmode == options::SygusInvTemplMode::POST);
templ = nm->mkNode(AND, d_trans_post[prog], d_templ_arg[prog]);
}
}
Trace("cegqi-inv") << " template (pre-substitution) : " << templ
<< std::endl;
Assert(!templ.isNull());
// get the variables
Node sfvl = SygusUtils::getSygusArgumentListForSynthFun(prog);
if (!sfvl.isNull())
{
std::vector<Node> prog_vars(sfvl.begin(), sfvl.end());
// subsitute the template arguments
Trace("cegqi-inv") << "vars : " << prog_templ_vars << " " << prog_vars
<< std::endl;
Assert(prog_templ_vars.size() == prog_vars.size());
templ = templ.substitute(prog_templ_vars.begin(),
prog_templ_vars.end(),
prog_vars.begin(),
prog_vars.end());
}
Trace("cegqi-inv") << " template : " << templ << std::endl;
d_templ[prog] = templ;
}
Node SygusTemplateInfer::getTemplate(Node prog) const
{
std::map<Node, Node>::const_iterator tmpl = d_templ.find(prog);
if (tmpl != d_templ.end())
{
return tmpl->second;
}
return Node::null();
}
Node SygusTemplateInfer::getTemplateArg(Node prog) const
{
std::map<Node, Node>::const_iterator tmpla = d_templ_arg.find(prog);
if (tmpla != d_templ_arg.end())
{
return tmpla->second;
}
return Node::null();
}
} // namespace quantifiers
} // namespace theory
} // namespace CVC4
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