Head

GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/theory/quantifiers/ematching/ho_trigger.cpp	Lines:	229	257	89.1 %
Date:	2021-09-16	Branches:	463	1128	41.0 %


/******************************************************************************
 * Top contributors (to current version):
 *   Andrew Reynolds, Mathias Preiner, Aina Niemetz
 *
 * This file is part of the cvc5 project.
 *
 * Copyright (c) 2009-2021 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.
 * ****************************************************************************
 *
 * Implementation of higher-order trigger class.
 */

#include "theory/quantifiers/ematching/ho_trigger.h"

#include <stack>

#include "theory/quantifiers/ho_term_database.h"
#include "theory/quantifiers/instantiate.h"
#include "theory/quantifiers/quantifiers_inference_manager.h"
#include "theory/quantifiers/quantifiers_registry.h"
#include "theory/quantifiers/quantifiers_state.h"
#include "theory/quantifiers/term_registry.h"
#include "theory/quantifiers/term_util.h"
#include "theory/uf/theory_uf_rewriter.h"
#include "util/hash.h"

using namespace cvc5::kind;

namespace cvc5 {
namespace theory {
namespace quantifiers {
namespace inst {

HigherOrderTrigger::HigherOrderTrigger(
    QuantifiersState& qs,
    QuantifiersInferenceManager& qim,
    QuantifiersRegistry& qr,
    TermRegistry& tr,
    Node q,
    std::vector<Node>& nodes,
    std::map<Node, std::vector<Node> >& ho_apps)
    : Trigger(qs, qim, qr, tr, q, nodes), d_ho_var_apps(ho_apps)
{
  NodeManager* nm = NodeManager::currentNM();
  // process the higher-order variable applications
  for (std::pair<const Node, std::vector<Node> >& as : d_ho_var_apps)
  {
    Node n = as.first;
    d_ho_var_list.push_back(n);
    TypeNode tn = n.getType();
    Assert(tn.isFunction());
    if (Trace.isOn("ho-quant-trigger"))
    {
      Trace("ho-quant-trigger") << "  have " << as.second.size();
      Trace("ho-quant-trigger") << " patterns with variable operator " << n
                                << ":" << std::endl;
      for (unsigned j = 0; j < as.second.size(); j++)
      {
        Trace("ho-quant-trigger") << "  " << as.second[j] << std::endl;
      }
    }
    if (d_ho_var_types.find(tn) == d_ho_var_types.end())
    {
      Trace("ho-quant-trigger") << "  type " << tn
                                << " needs higher-order matching." << std::endl;
      d_ho_var_types.insert(tn);
    }
    // make the bound variable lists
    d_ho_var_bvl[n] = nm->getBoundVarListForFunctionType(tn);
    for (const Node& nc : d_ho_var_bvl[n])
    {
      d_ho_var_bvs[n].push_back(nc);
    }
  }
}

HigherOrderTrigger::~HigherOrderTrigger() {}
void HigherOrderTrigger::collectHoVarApplyTerms(
    Node q, Node& n, std::map<Node, std::vector<Node> >& apps)
{
  std::vector<Node> ns;
  ns.push_back(n);
  collectHoVarApplyTerms(q, ns, apps);
  Assert(ns.size() == 1);
  n = ns[0];
}

void HigherOrderTrigger::collectHoVarApplyTerms(
    Node q, std::vector<Node>& ns, std::map<Node, std::vector<Node> >& apps)
{
  std::unordered_map<TNode, Node> visited;
  std::unordered_map<TNode, Node>::iterator it;
  // whether the visited node is a child of a HO_APPLY chain
  std::unordered_map<TNode, bool> withinApply;
  std::vector<TNode> visit;
  TNode cur;
  for (unsigned i = 0, size = ns.size(); i < size; i++)
  {
    visit.push_back(ns[i]);
    withinApply[ns[i]] = false;
    do
    {
      cur = visit.back();
      visit.pop_back();

      it = visited.find(cur);
      if (it == visited.end())
      {
        // do not look in nested quantifiers
        if (cur.getKind() == FORALL)
        {
          visited[cur] = cur;
        }
        else
        {
          bool curWithinApply = withinApply[cur];
          visited[cur] = Node::null();
          visit.push_back(cur);
          for (unsigned j = 0, sizec = cur.getNumChildren(); j < sizec; j++)
          {
            withinApply[cur[j]] = curWithinApply && j == 0;
            visit.push_back(cur[j]);
          }
        }
      }
      else if (it->second.isNull())
      {
        // carry the conversion
        Node ret = cur;
        bool childChanged = false;
        std::vector<Node> children;
        if (cur.getMetaKind() == kind::metakind::PARAMETERIZED)
        {
          children.push_back(cur.getOperator());
        }
        for (const Node& nc : cur)
        {
          it = visited.find(nc);
          Assert(it != visited.end());
          Assert(!it->second.isNull());
          childChanged = childChanged || nc != it->second;
          children.push_back(it->second);
        }
        if (childChanged)
        {
          ret = NodeManager::currentNM()->mkNode(cur.getKind(), children);
        }
        // now, convert and store the application
        if (!withinApply[cur])
        {
          TNode op;
          if (ret.getKind() == kind::APPLY_UF)
          {
            // could be a fully applied function variable
            op = ret.getOperator();
          }
          else if (ret.getKind() == kind::HO_APPLY)
          {
            op = ret;
            while (op.getKind() == kind::HO_APPLY)
            {
              op = op[0];
            }
          }
          if (!op.isNull())
          {
            if (op.getKind() == kind::INST_CONSTANT)
            {
              Assert(TermUtil::getInstConstAttr(ret) == q);
              Trace("ho-quant-trigger-debug")
                  << "Ho variable apply term : " << ret << " with head " << op
                  << std::endl;
              if (ret.getKind() == kind::APPLY_UF)
              {
                Node prev = ret;
                // for consistency, convert to HO_APPLY if fully applied
                ret = uf::TheoryUfRewriter::getHoApplyForApplyUf(ret);
              }
              apps[op].push_back(ret);
            }
          }
        }
        visited[cur] = ret;
      }
    } while (!visit.empty());

    // store the conversion
    Assert(visited.find(ns[i]) != visited.end());
    ns[i] = visited[ns[i]];
  }
}

uint64_t HigherOrderTrigger::addInstantiations()
{
  // call the base class implementation
  uint64_t addedFoLemmas = Trigger::addInstantiations();
  // also adds predicate lemms to force app completion
  uint64_t addedHoLemmas = addHoTypeMatchPredicateLemmas();
  return addedHoLemmas + addedFoLemmas;
}

bool HigherOrderTrigger::sendInstantiation(std::vector<Node>& m, InferenceId id)
{
  if (options::hoMatching())
  {
    // get substitution corresponding to m
    std::vector<TNode> vars;
    std::vector<TNode> subs;
    for (unsigned i = 0, size = d_quant[0].getNumChildren(); i < size; i++)
    {
      subs.push_back(m[i]);
      vars.push_back(d_qreg.getInstantiationConstant(d_quant, i));
    }

    Trace("ho-unif-debug") << "Run higher-order unification..." << std::endl;

    // get the substituted form of all variable-operator ho application terms
    std::map<TNode, std::vector<Node> > ho_var_apps_subs;
    for (std::pair<const Node, std::vector<Node> >& ha : d_ho_var_apps)
    {
      TNode var = ha.first;
      for (unsigned j = 0, size = ha.second.size(); j < size; j++)
      {
        TNode app = ha.second[j];
        Node sapp =
            app.substitute(vars.begin(), vars.end(), subs.begin(), subs.end());
        ho_var_apps_subs[var].push_back(sapp);
        Trace("ho-unif-debug") << "  app[" << var << "] : " << app << " -> "
                               << sapp << std::endl;
      }
    }

    // compute argument vectors for each variable
    d_lchildren.clear();
    d_arg_to_arg_rep.clear();
    d_arg_vector.clear();
    for (std::pair<const TNode, std::vector<Node> >& ha : ho_var_apps_subs)
    {
      TNode var = ha.first;
      unsigned vnum = var.getAttribute(InstVarNumAttribute());
      TNode value = m[vnum];
      Trace("ho-unif-debug") << "  val[" << var << "] = " << value << std::endl;

      Trace("ho-unif-debug2") << "initialize lambda information..."
                              << std::endl;
      // initialize the lambda children
      d_lchildren[vnum].push_back(value);
      std::map<TNode, std::vector<Node> >::iterator ithb =
          d_ho_var_bvs.find(var);
      Assert(ithb != d_ho_var_bvs.end());
      d_lchildren[vnum].insert(
          d_lchildren[vnum].end(), ithb->second.begin(), ithb->second.end());

      Trace("ho-unif-debug2") << "compute fixed arguments..." << std::endl;
      // compute for each argument if it is only applied to a fixed value modulo
      // equality
      std::map<unsigned, Node> fixed_vals;
      for (unsigned i = 0; i < ha.second.size(); i++)
      {
        std::vector<TNode> args;
        // must substitute the operator we matched with the original
        // higher-order variable (var) that matched it. This ensures that the
        // argument vector (args) below is of the proper length. This handles,
        // for example, matches like:
        //   (@ x y) with (@ (@ k1 k2) k3)
        // where k3 but not k2 should be an argument of the match.
        Node hmatch = ha.second[i];
        Trace("ho-unif-debug2") << "Match is " << hmatch << std::endl;
        hmatch = hmatch.substitute(value, var);
        Trace("ho-unif-debug2") << "Pre-subs match is " << hmatch << std::endl;
        Node f = uf::TheoryUfRewriter::decomposeHoApply(hmatch, args);
        // Assert( f==value );
        for (unsigned k = 0, size = args.size(); k < size; k++)
        {
          // must now subsitute back, to handle cases like
          // (@ x y) matching (@ t (@ t s))
          // where the above substitution would produce (@ x (@ x s)),
          // but the argument should be (@ t s).
          args[k] = args[k].substitute(var, value);
          Node val = args[k];
          std::map<unsigned, Node>::iterator itf = fixed_vals.find(k);
          if (itf == fixed_vals.end())
          {
            fixed_vals[k] = val;
          }
          else if (!itf->second.isNull())
          {
            if (!d_qstate.areEqual(itf->second, args[k]))
            {
              if (!d_treg.getTermDatabase()->isEntailed(
                      itf->second.eqNode(args[k]), true))
              {
                fixed_vals[k] = Node::null();
              }
            }
          }
        }
      }
      if (Trace.isOn("ho-unif-debug"))
      {
        for (std::map<unsigned, Node>::iterator itf = fixed_vals.begin();
             itf != fixed_vals.end();
             ++itf)
        {
          Trace("ho-unif-debug") << "  arg[" << var << "][" << itf->first
                                 << "] : " << itf->second << std::endl;
        }
      }

      // now construct argument vectors
      Trace("ho-unif-debug2") << "compute argument vectors..." << std::endl;
      std::map<Node, unsigned> arg_to_rep;
      for (unsigned index = 0, size = ithb->second.size(); index < size;
           index++)
      {
        Node bv_at_index = ithb->second[index];
        std::map<unsigned, Node>::iterator itf = fixed_vals.find(index);
        Trace("ho-unif-debug") << "  * arg[" << var << "][" << index << "]";
        if (itf != fixed_vals.end())
        {
          if (!itf->second.isNull())
          {
            Node r = d_qstate.getRepresentative(itf->second);
            std::map<Node, unsigned>::iterator itfr = arg_to_rep.find(r);
            if (itfr != arg_to_rep.end())
            {
              d_arg_to_arg_rep[vnum][index] = itfr->second;
              // function applied to equivalent values at multiple arguments,
              // can permute variables
              d_arg_vector[vnum][itfr->second].push_back(bv_at_index);
              Trace("ho-unif-debug") << " = { self } ++ arg[" << var << "]["
                                     << itfr->second << "]" << std::endl;
            }
            else
            {
              arg_to_rep[r] = index;
              // function applied to single value, can either use variable or
              // value at this argument position
              d_arg_vector[vnum][index].push_back(bv_at_index);
              d_arg_vector[vnum][index].push_back(itf->second);
              if (!options::hoMatchingVarArgPriority())
              {
                std::reverse(d_arg_vector[vnum][index].begin(),
                             d_arg_vector[vnum][index].end());
              }
              Trace("ho-unif-debug") << " = { self, " << itf->second << " } "
                                     << std::endl;
            }
          }
          else
          {
            // function is applied to disequal values, can only use variable at
            // this argument position
            d_arg_vector[vnum][index].push_back(bv_at_index);
            Trace("ho-unif-debug") << " = { self } (disequal)" << std::endl;
          }
        }
        else
        {
          // argument is irrelevant to matching, assume identity variable
          d_arg_vector[vnum][index].push_back(bv_at_index);
          Trace("ho-unif-debug") << " = { self } (irrelevant)" << std::endl;
        }
      }
      Trace("ho-unif-debug2") << "finished." << std::endl;
    }

    bool ret = sendInstantiation(m, 0);
    Trace("ho-unif-debug") << "Finished, success = " << ret << std::endl;
    return ret;
  }
  else
  {
    // do not run higher-order matching
    return d_qim.getInstantiate()->addInstantiation(d_quant, m, id);
  }
}

// recursion depth limited by number of arguments of higher order variables
// occurring as pattern operators (very small)
bool HigherOrderTrigger::sendInstantiation(std::vector<Node>& m,
                                           size_t var_index)
{
  Trace("ho-unif-debug2") << "send inst " << var_index << " / "
                          << d_ho_var_list.size() << std::endl;
  if (var_index == d_ho_var_list.size())
  {
    // we now have an instantiation to try
    return d_qim.getInstantiate()->addInstantiation(
        d_quant, m, InferenceId::QUANTIFIERS_INST_E_MATCHING_HO);
  }
  else
  {
    Node var = d_ho_var_list[var_index];
    unsigned vnum = var.getAttribute(InstVarNumAttribute());
    Assert(vnum < m.size());
    Node value = m[vnum];
    Assert(d_lchildren[vnum][0] == value);
    Assert(d_ho_var_bvl.find(var) != d_ho_var_bvl.end());

    // now, recurse on arguments to enumerate equivalent matching lambda
    // expressions
    bool ret =
        sendInstantiationArg(m, var_index, vnum, 0, d_ho_var_bvl[var], false);

    // reset the value
    m[vnum] = value;

    return ret;
  }
}

bool HigherOrderTrigger::sendInstantiationArg(std::vector<Node>& m,
                                              unsigned var_index,
                                              unsigned vnum,
                                              unsigned arg_index,
                                              Node lbvl,
                                              bool arg_changed)
{
  Trace("ho-unif-debug2") << "send inst arg " << arg_index << " / "
                          << lbvl.getNumChildren() << std::endl;
  if (arg_index == lbvl.getNumChildren())
  {
    // construct the lambda
    if (arg_changed)
    {
      Trace("ho-unif-debug2")
          << "  make lambda from children: " << d_lchildren[vnum] << std::endl;
      Node body =
          NodeManager::currentNM()->mkNode(kind::APPLY_UF, d_lchildren[vnum]);
      Trace("ho-unif-debug2") << "  got " << body << std::endl;
      Node lam = NodeManager::currentNM()->mkNode(kind::LAMBDA, lbvl, body);
      m[vnum] = lam;
      Trace("ho-unif-debug2") << "  try " << vnum << " -> " << lam << std::endl;
    }
    return sendInstantiation(m, var_index + 1);
  }
  else
  {
    std::map<unsigned, unsigned>::iterator itr =
        d_arg_to_arg_rep[vnum].find(arg_index);
    unsigned rindex =
        itr != d_arg_to_arg_rep[vnum].end() ? itr->second : arg_index;
    std::map<unsigned, std::vector<Node> >::iterator itv =
        d_arg_vector[vnum].find(rindex);
    Assert(itv != d_arg_vector[vnum].end());
    Node prev = lbvl[arg_index];
    bool ret = false;
    // try each argument in the vector
    for (unsigned i = 0, size = itv->second.size(); i < size; i++)
    {
      bool new_arg_changed = arg_changed || prev != itv->second[i];
      d_lchildren[vnum][arg_index + 1] = itv->second[i];
      if (sendInstantiationArg(
              m, var_index, vnum, arg_index + 1, lbvl, new_arg_changed))
      {
        ret = true;
        break;
      }
    }
    // clean up
    d_lchildren[vnum][arg_index + 1] = prev;
    return ret;
  }
}

uint64_t HigherOrderTrigger::addHoTypeMatchPredicateLemmas()
{
  if (d_ho_var_types.empty())
  {
    return 0;
  }
  Trace("ho-quant-trigger") << "addHoTypeMatchPredicateLemmas..." << std::endl;
  uint64_t numLemmas = 0;
  // this forces expansion of APPLY_UF terms to curried HO_APPLY chains
  TermDb* tdb = d_treg.getTermDatabase();
  unsigned size = tdb->getNumOperators();
  NodeManager* nm = NodeManager::currentNM();
  for (unsigned j = 0; j < size; j++)
  {
    Node f = tdb->getOperator(j);
    if (f.isVar())
    {
      TypeNode tn = f.getType();
      if (tn.isFunction())
      {
        std::vector<TypeNode> argTypes = tn.getArgTypes();
        Assert(argTypes.size() > 0);
        TypeNode range = tn.getRangeType();
        // for each function type suffix of the type of f, for example if
        // f : (Int -> (Int -> Int))
        // we iterate with stn = (Int -> (Int -> Int)) and (Int -> Int)
        for (unsigned a = 0, arg_size = argTypes.size(); a < arg_size; a++)
        {
          std::vector<TypeNode> sargts;
          sargts.insert(sargts.begin(), argTypes.begin() + a, argTypes.end());
          Assert(sargts.size() > 0);
          TypeNode stn = nm->mkFunctionType(sargts, range);
          Trace("ho-quant-trigger-debug")
              << "For " << f << ", check " << stn << "..." << std::endl;
          // if a variable of this type occurs in this trigger
          if (d_ho_var_types.find(stn) != d_ho_var_types.end())
          {
            Node u = HoTermDb::getHoTypeMatchPredicate(tn);
            Node au = nm->mkNode(kind::APPLY_UF, u, f);
            if (d_qim.addPendingLemma(au,
                                      InferenceId::QUANTIFIERS_HO_MATCH_PRED))
            {
              // this forces f to be a first-class member of the quantifier-free
              // equality engine, which in turn forces the quantifier-free
              // theory solver to expand it to an HO_APPLY chain.
              Trace("ho-quant")
                  << "Added ho match predicate lemma : " << au << std::endl;
              numLemmas++;
            }
          }
        }
      }
    }
  }

  return numLemmas;
}

}  // namespace inst
}  // namespace quantifiers
}  // namespace theory
}  // namespace cvc5


Generated by: GCOVR (Version 3.2)

Line	Exec	Source
1		/******************************************************************************
2		* Top contributors (to current version):
3		* Andrew Reynolds, Mathias Preiner, Aina Niemetz
4		*
5		* This file is part of the cvc5 project.
6		*
7		* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
8		* in the top-level source directory and their institutional affiliations.
9		* All rights reserved. See the file COPYING in the top-level source
10		* directory for licensing information.
11		* ****************************************************************************
12		*
13		* Implementation of higher-order trigger class.
14		*/
15
16		#include "theory/quantifiers/ematching/ho_trigger.h"
17
18		#include <stack>
19
20		#include "theory/quantifiers/ho_term_database.h"
21		#include "theory/quantifiers/instantiate.h"
22		#include "theory/quantifiers/quantifiers_inference_manager.h"
23		#include "theory/quantifiers/quantifiers_registry.h"
24		#include "theory/quantifiers/quantifiers_state.h"
25		#include "theory/quantifiers/term_registry.h"
26		#include "theory/quantifiers/term_util.h"
27		#include "theory/uf/theory_uf_rewriter.h"
28		#include "util/hash.h"
29
30		using namespace cvc5::kind;
31
32		namespace cvc5 {
33		namespace theory {
34		namespace quantifiers {
35		namespace inst {
36
37	36	HigherOrderTrigger::HigherOrderTrigger(
38		QuantifiersState& qs,
39		QuantifiersInferenceManager& qim,
40		QuantifiersRegistry& qr,
41		TermRegistry& tr,
42		Node q,
43		std::vector<Node>& nodes,
44	36	std::map<Node, std::vector<Node> >& ho_apps)
45	36	: Trigger(qs, qim, qr, tr, q, nodes), d_ho_var_apps(ho_apps)
46		{
47	36	NodeManager* nm = NodeManager::currentNM();
48		// process the higher-order variable applications
49	84	for (std::pair<const Node, std::vector<Node> >& as : d_ho_var_apps)
50		{
51	96	Node n = as.first;
52	48	d_ho_var_list.push_back(n);
53	96	TypeNode tn = n.getType();
54	48	Assert(tn.isFunction());
55	48	if (Trace.isOn("ho-quant-trigger"))
56		{
57		Trace("ho-quant-trigger") << " have " << as.second.size();
58		Trace("ho-quant-trigger") << " patterns with variable operator " << n
59		<< ":" << std::endl;
60		for (unsigned j = 0; j < as.second.size(); j++)
61		{
62		Trace("ho-quant-trigger") << " " << as.second[j] << std::endl;
63		}
64		}
65	48	if (d_ho_var_types.find(tn) == d_ho_var_types.end())
66		{
67	96	Trace("ho-quant-trigger") << " type " << tn
68	48	<< " needs higher-order matching." << std::endl;
69	48	d_ho_var_types.insert(tn);
70		}
71		// make the bound variable lists
72	48	d_ho_var_bvl[n] = nm->getBoundVarListForFunctionType(tn);
73	120	for (const Node& nc : d_ho_var_bvl[n])
74		{
75	72	d_ho_var_bvs[n].push_back(nc);
76		}
77		}
78	36	}
79
80	72	HigherOrderTrigger::~HigherOrderTrigger() {}
81		void HigherOrderTrigger::collectHoVarApplyTerms(
82		Node q, Node& n, std::map<Node, std::vector<Node> >& apps)
83		{
84		std::vector<Node> ns;
85		ns.push_back(n);
86		collectHoVarApplyTerms(q, ns, apps);
87		Assert(ns.size() == 1);
88		n = ns[0];
89		}
90
91	17035	void HigherOrderTrigger::collectHoVarApplyTerms(
92		Node q, std::vector<Node>& ns, std::map<Node, std::vector<Node> >& apps)
93		{
94	34070	std::unordered_map<TNode, Node> visited;
95	17035	std::unordered_map<TNode, Node>::iterator it;
96		// whether the visited node is a child of a HO_APPLY chain
97	34070	std::unordered_map<TNode, bool> withinApply;
98	34070	std::vector<TNode> visit;
99	34070	TNode cur;
100	35661	for (unsigned i = 0, size = ns.size(); i < size; i++)
101		{
102	18626	visit.push_back(ns[i]);
103	18626	withinApply[ns[i]] = false;
104	202162	do
105		{
106	220788	cur = visit.back();
107	220788	visit.pop_back();
108
109	220788	it = visited.find(cur);
110	220788	if (it == visited.end())
111		{
112		// do not look in nested quantifiers
113	108415	if (cur.getKind() == FORALL)
114		{
115		visited[cur] = cur;
116		}
117		else
118		{
119	108415	bool curWithinApply = withinApply[cur];
120	108415	visited[cur] = Node::null();
121	108415	visit.push_back(cur);
122	202162	for (unsigned j = 0, sizec = cur.getNumChildren(); j < sizec; j++)
123		{
124	93747	withinApply[cur[j]] = curWithinApply && j == 0;
125	93747	visit.push_back(cur[j]);
126		}
127		}
128		}
129	112373	else if (it->second.isNull())
130		{
131		// carry the conversion
132	216830	Node ret = cur;
133	108415	bool childChanged = false;
134	216830	std::vector<Node> children;
135	108415	if (cur.getMetaKind() == kind::metakind::PARAMETERIZED)
136		{
137	43203	children.push_back(cur.getOperator());
138		}
139	202162	for (const Node& nc : cur)
140		{
141	93747	it = visited.find(nc);
142	93747	Assert(it != visited.end());
143	93747	Assert(!it->second.isNull());
144	93747	childChanged = childChanged \|\| nc != it->second;
145	93747	children.push_back(it->second);
146		}
147	108415	if (childChanged)
148		{
149	40	ret = NodeManager::currentNM()->mkNode(cur.getKind(), children);
150		}
151		// now, convert and store the application
152	108415	if (!withinApply[cur])
153		{
154	216830	TNode op;
155	108415	if (ret.getKind() == kind::APPLY_UF)
156		{
157		// could be a fully applied function variable
158	37222	op = ret.getOperator();
159		}
160	71193	else if (ret.getKind() == kind::HO_APPLY)
161		{
162	113	op = ret;
163	407	while (op.getKind() == kind::HO_APPLY)
164		{
165	147	op = op[0];
166		}
167		}
168	108415	if (!op.isNull())
169		{
170	37335	if (op.getKind() == kind::INST_CONSTANT)
171		{
172	48	Assert(TermUtil::getInstConstAttr(ret) == q);
173	96	Trace("ho-quant-trigger-debug")
174	48	<< "Ho variable apply term : " << ret << " with head " << op
175	48	<< std::endl;
176	48	if (ret.getKind() == kind::APPLY_UF)
177		{
178	80	Node prev = ret;
179		// for consistency, convert to HO_APPLY if fully applied
180	40	ret = uf::TheoryUfRewriter::getHoApplyForApplyUf(ret);
181		}
182	48	apps[op].push_back(ret);
183		}
184		}
185		}
186	108415	visited[cur] = ret;
187		}
188	220788	} while (!visit.empty());
189
190		// store the conversion
191	18626	Assert(visited.find(ns[i]) != visited.end());
192	18626	ns[i] = visited[ns[i]];
193		}
194	17035	}
195
196	108	uint64_t HigherOrderTrigger::addInstantiations()
197		{
198		// call the base class implementation
199	108	uint64_t addedFoLemmas = Trigger::addInstantiations();
200		// also adds predicate lemms to force app completion
201	108	uint64_t addedHoLemmas = addHoTypeMatchPredicateLemmas();
202	108	return addedHoLemmas + addedFoLemmas;
203		}
204
205	192	bool HigherOrderTrigger::sendInstantiation(std::vector<Node>& m, InferenceId id)
206		{
207	192	if (options::hoMatching())
208		{
209		// get substitution corresponding to m
210	384	std::vector<TNode> vars;
211	384	std::vector<TNode> subs;
212	684	for (unsigned i = 0, size = d_quant[0].getNumChildren(); i < size; i++)
213		{
214	492	subs.push_back(m[i]);
215	492	vars.push_back(d_qreg.getInstantiationConstant(d_quant, i));
216		}
217
218	192	Trace("ho-unif-debug") << "Run higher-order unification..." << std::endl;
219
220		// get the substituted form of all variable-operator ho application terms
221	384	std::map<TNode, std::vector<Node> > ho_var_apps_subs;
222	432	for (std::pair<const Node, std::vector<Node> >& ha : d_ho_var_apps)
223		{
224	480	TNode var = ha.first;
225	480	for (unsigned j = 0, size = ha.second.size(); j < size; j++)
226		{
227	480	TNode app = ha.second[j];
228		Node sapp =
229	480	app.substitute(vars.begin(), vars.end(), subs.begin(), subs.end());
230	240	ho_var_apps_subs[var].push_back(sapp);
231	480	Trace("ho-unif-debug") << " app[" << var << "] : " << app << " -> "
232	240	<< sapp << std::endl;
233		}
234		}
235
236		// compute argument vectors for each variable
237	192	d_lchildren.clear();
238	192	d_arg_to_arg_rep.clear();
239	192	d_arg_vector.clear();
240	432	for (std::pair<const TNode, std::vector<Node> >& ha : ho_var_apps_subs)
241		{
242	480	TNode var = ha.first;
243	240	unsigned vnum = var.getAttribute(InstVarNumAttribute());
244	480	TNode value = m[vnum];
245	240	Trace("ho-unif-debug") << " val[" << var << "] = " << value << std::endl;
246
247	480	Trace("ho-unif-debug2") << "initialize lambda information..."
248	240	<< std::endl;
249		// initialize the lambda children
250	240	d_lchildren[vnum].push_back(value);
251		std::map<TNode, std::vector<Node> >::iterator ithb =
252	240	d_ho_var_bvs.find(var);
253	240	Assert(ithb != d_ho_var_bvs.end());
254	480	d_lchildren[vnum].insert(
255	480	d_lchildren[vnum].end(), ithb->second.begin(), ithb->second.end());
256
257	240	Trace("ho-unif-debug2") << "compute fixed arguments..." << std::endl;
258		// compute for each argument if it is only applied to a fixed value modulo
259		// equality
260	480	std::map<unsigned, Node> fixed_vals;
261	480	for (unsigned i = 0; i < ha.second.size(); i++)
262		{
263	480	std::vector<TNode> args;
264		// must substitute the operator we matched with the original
265		// higher-order variable (var) that matched it. This ensures that the
266		// argument vector (args) below is of the proper length. This handles,
267		// for example, matches like:
268		// (@ x y) with (@ (@ k1 k2) k3)
269		// where k3 but not k2 should be an argument of the match.
270	480	Node hmatch = ha.second[i];
271	240	Trace("ho-unif-debug2") << "Match is " << hmatch << std::endl;
272	240	hmatch = hmatch.substitute(value, var);
273	240	Trace("ho-unif-debug2") << "Pre-subs match is " << hmatch << std::endl;
274	480	Node f = uf::TheoryUfRewriter::decomposeHoApply(hmatch, args);
275		// Assert( f==value );
276	616	for (unsigned k = 0, size = args.size(); k < size; k++)
277		{
278		// must now subsitute back, to handle cases like
279		// (@ x y) matching (@ t (@ t s))
280		// where the above substitution would produce (@ x (@ x s)),
281		// but the argument should be (@ t s).
282	376	args[k] = args[k].substitute(var, value);
283	752	Node val = args[k];
284	376	std::map<unsigned, Node>::iterator itf = fixed_vals.find(k);
285	376	if (itf == fixed_vals.end())
286		{
287	376	fixed_vals[k] = val;
288		}
289		else if (!itf->second.isNull())
290		{
291		if (!d_qstate.areEqual(itf->second, args[k]))
292		{
293		if (!d_treg.getTermDatabase()->isEntailed(
294		itf->second.eqNode(args[k]), true))
295		{
296		fixed_vals[k] = Node::null();
297		}
298		}
299		}
300		}
301		}
302	240	if (Trace.isOn("ho-unif-debug"))
303		{
304		for (std::map<unsigned, Node>::iterator itf = fixed_vals.begin();
305		itf != fixed_vals.end();
306		++itf)
307		{
308		Trace("ho-unif-debug") << " arg[" << var << "][" << itf->first
309		<< "] : " << itf->second << std::endl;
310		}
311		}
312
313		// now construct argument vectors
314	240	Trace("ho-unif-debug2") << "compute argument vectors..." << std::endl;
315	480	std::map<Node, unsigned> arg_to_rep;
316	640	for (unsigned index = 0, size = ithb->second.size(); index < size;
317		index++)
318		{
319	800	Node bv_at_index = ithb->second[index];
320	400	std::map<unsigned, Node>::iterator itf = fixed_vals.find(index);
321	400	Trace("ho-unif-debug") << " * arg[" << var << "][" << index << "]";
322	400	if (itf != fixed_vals.end())
323		{
324	376	if (!itf->second.isNull())
325		{
326	752	Node r = d_qstate.getRepresentative(itf->second);
327	376	std::map<Node, unsigned>::iterator itfr = arg_to_rep.find(r);
328	376	if (itfr != arg_to_rep.end())
329		{
330	52	d_arg_to_arg_rep[vnum][index] = itfr->second;
331		// function applied to equivalent values at multiple arguments,
332		// can permute variables
333	52	d_arg_vector[vnum][itfr->second].push_back(bv_at_index);
334	104	Trace("ho-unif-debug") << " = { self } ++ arg[" << var << "]["
335	52	<< itfr->second << "]" << std::endl;
336		}
337		else
338		{
339	324	arg_to_rep[r] = index;
340		// function applied to single value, can either use variable or
341		// value at this argument position
342	324	d_arg_vector[vnum][index].push_back(bv_at_index);
343	324	d_arg_vector[vnum][index].push_back(itf->second);
344	324	if (!options::hoMatchingVarArgPriority())
345		{
346		std::reverse(d_arg_vector[vnum][index].begin(),
347		d_arg_vector[vnum][index].end());
348		}
349	648	Trace("ho-unif-debug") << " = { self, " << itf->second << " } "
350	324	<< std::endl;
351		}
352		}
353		else
354		{
355		// function is applied to disequal values, can only use variable at
356		// this argument position
357		d_arg_vector[vnum][index].push_back(bv_at_index);
358		Trace("ho-unif-debug") << " = { self } (disequal)" << std::endl;
359		}
360		}
361		else
362		{
363		// argument is irrelevant to matching, assume identity variable
364	24	d_arg_vector[vnum][index].push_back(bv_at_index);
365	24	Trace("ho-unif-debug") << " = { self } (irrelevant)" << std::endl;
366		}
367		}
368	240	Trace("ho-unif-debug2") << "finished." << std::endl;
369		}
370
371	192	bool ret = sendInstantiation(m, 0);
372	192	Trace("ho-unif-debug") << "Finished, success = " << ret << std::endl;
373	192	return ret;
374		}
375		else
376		{
377		// do not run higher-order matching
378		return d_qim.getInstantiate()->addInstantiation(d_quant, m, id);
379		}
380		}
381
382		// recursion depth limited by number of arguments of higher order variables
383		// occurring as pattern operators (very small)
384	906	bool HigherOrderTrigger::sendInstantiation(std::vector<Node>& m,
385		size_t var_index)
386		{
387	1812	Trace("ho-unif-debug2") << "send inst " << var_index << " / "
388	906	<< d_ho_var_list.size() << std::endl;
389	906	if (var_index == d_ho_var_list.size())
390		{
391		// we now have an instantiation to try
392	1204	return d_qim.getInstantiate()->addInstantiation(
393	602	d_quant, m, InferenceId::QUANTIFIERS_INST_E_MATCHING_HO);
394		}
395		else
396		{
397	608	Node var = d_ho_var_list[var_index];
398	304	unsigned vnum = var.getAttribute(InstVarNumAttribute());
399	304	Assert(vnum < m.size());
400	608	Node value = m[vnum];
401	304	Assert(d_lchildren[vnum][0] == value);
402	304	Assert(d_ho_var_bvl.find(var) != d_ho_var_bvl.end());
403
404		// now, recurse on arguments to enumerate equivalent matching lambda
405		// expressions
406		bool ret =
407	304	sendInstantiationArg(m, var_index, vnum, 0, d_ho_var_bvl[var], false);
408
409		// reset the value
410	304	m[vnum] = value;
411
412	304	return ret;
413		}
414		}
415
416	1272	bool HigherOrderTrigger::sendInstantiationArg(std::vector<Node>& m,
417		unsigned var_index,
418		unsigned vnum,
419		unsigned arg_index,
420		Node lbvl,
421		bool arg_changed)
422		{
423	2544	Trace("ho-unif-debug2") << "send inst arg " << arg_index << " / "
424	1272	<< lbvl.getNumChildren() << std::endl;
425	1272	if (arg_index == lbvl.getNumChildren())
426		{
427		// construct the lambda
428	714	if (arg_changed)
429		{
430	876	Trace("ho-unif-debug2")
431	438	<< " make lambda from children: " << d_lchildren[vnum] << std::endl;
432		Node body =
433	876	NodeManager::currentNM()->mkNode(kind::APPLY_UF, d_lchildren[vnum]);
434	438	Trace("ho-unif-debug2") << " got " << body << std::endl;
435	876	Node lam = NodeManager::currentNM()->mkNode(kind::LAMBDA, lbvl, body);
436	438	m[vnum] = lam;
437	438	Trace("ho-unif-debug2") << " try " << vnum << " -> " << lam << std::endl;
438		}
439	714	return sendInstantiation(m, var_index + 1);
440		}
441		else
442		{
443		std::map<unsigned, unsigned>::iterator itr =
444	558	d_arg_to_arg_rep[vnum].find(arg_index);
445		unsigned rindex =
446	558	itr != d_arg_to_arg_rep[vnum].end() ? itr->second : arg_index;
447		std::map<unsigned, std::vector<Node> >::iterator itv =
448	558	d_arg_vector[vnum].find(rindex);
449	558	Assert(itv != d_arg_vector[vnum].end());
450	1116	Node prev = lbvl[arg_index];
451	558	bool ret = false;
452		// try each argument in the vector
453	1196	for (unsigned i = 0, size = itv->second.size(); i < size; i++)
454		{
455	968	bool new_arg_changed = arg_changed \|\| prev != itv->second[i];
456	968	d_lchildren[vnum][arg_index + 1] = itv->second[i];
457	968	if (sendInstantiationArg(
458		m, var_index, vnum, arg_index + 1, lbvl, new_arg_changed))
459		{
460	330	ret = true;
461	330	break;
462		}
463		}
464		// clean up
465	558	d_lchildren[vnum][arg_index + 1] = prev;
466	558	return ret;
467		}
468		}
469
470	108	uint64_t HigherOrderTrigger::addHoTypeMatchPredicateLemmas()
471		{
472	108	if (d_ho_var_types.empty())
473		{
474		return 0;
475		}
476	108	Trace("ho-quant-trigger") << "addHoTypeMatchPredicateLemmas..." << std::endl;
477	108	uint64_t numLemmas = 0;
478		// this forces expansion of APPLY_UF terms to curried HO_APPLY chains
479	108	TermDb* tdb = d_treg.getTermDatabase();
480	108	unsigned size = tdb->getNumOperators();
481	108	NodeManager* nm = NodeManager::currentNM();
482	768	for (unsigned j = 0; j < size; j++)
483		{
484	1320	Node f = tdb->getOperator(j);
485	660	if (f.isVar())
486		{
487	1024	TypeNode tn = f.getType();
488	512	if (tn.isFunction())
489		{
490	1024	std::vector<TypeNode> argTypes = tn.getArgTypes();
491	512	Assert(argTypes.size() > 0);
492	1024	TypeNode range = tn.getRangeType();
493		// for each function type suffix of the type of f, for example if
494		// f : (Int -> (Int -> Int))
495		// we iterate with stn = (Int -> (Int -> Int)) and (Int -> Int)
496	1112	for (unsigned a = 0, arg_size = argTypes.size(); a < arg_size; a++)
497		{
498	1200	std::vector<TypeNode> sargts;
499	600	sargts.insert(sargts.begin(), argTypes.begin() + a, argTypes.end());
500	600	Assert(sargts.size() > 0);
501	1200	TypeNode stn = nm->mkFunctionType(sargts, range);
502	1200	Trace("ho-quant-trigger-debug")
503	600	<< "For " << f << ", check " << stn << "..." << std::endl;
504		// if a variable of this type occurs in this trigger
505	600	if (d_ho_var_types.find(stn) != d_ho_var_types.end())
506		{
507	536	Node u = HoTermDb::getHoTypeMatchPredicate(tn);
508	536	Node au = nm->mkNode(kind::APPLY_UF, u, f);
509	268	if (d_qim.addPendingLemma(au,
510		InferenceId::QUANTIFIERS_HO_MATCH_PRED))
511		{
512		// this forces f to be a first-class member of the quantifier-free
513		// equality engine, which in turn forces the quantifier-free
514		// theory solver to expand it to an HO_APPLY chain.
515	116	Trace("ho-quant")
516	58	<< "Added ho match predicate lemma : " << au << std::endl;
517	58	numLemmas++;
518		}
519		}
520		}
521		}
522		}
523		}
524
525	108	return numLemmas;
526		}
527
528		} // namespace inst
529		} // namespace quantifiers
530		} // namespace theory
531	29577	} // namespace cvc5