Head

GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/theory/quantifiers/ematching/ho_trigger.cpp	Lines:	229	257	89.1 %
Date:	2021-08-16	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 <stack>

#include "theory/quantifiers/ematching/ho_trigger.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_database.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 = tdb->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 <stack>
17
18		#include "theory/quantifiers/ematching/ho_trigger.h"
19		#include "theory/quantifiers/instantiate.h"
20		#include "theory/quantifiers/quantifiers_inference_manager.h"
21		#include "theory/quantifiers/quantifiers_registry.h"
22		#include "theory/quantifiers/quantifiers_state.h"
23		#include "theory/quantifiers/term_database.h"
24		#include "theory/quantifiers/term_registry.h"
25		#include "theory/quantifiers/term_util.h"
26		#include "theory/uf/theory_uf_rewriter.h"
27		#include "util/hash.h"
28
29		using namespace cvc5::kind;
30
31		namespace cvc5 {
32		namespace theory {
33		namespace quantifiers {
34		namespace inst {
35
36	36	HigherOrderTrigger::HigherOrderTrigger(
37		QuantifiersState& qs,
38		QuantifiersInferenceManager& qim,
39		QuantifiersRegistry& qr,
40		TermRegistry& tr,
41		Node q,
42		std::vector<Node>& nodes,
43	36	std::map<Node, std::vector<Node> >& ho_apps)
44	36	: Trigger(qs, qim, qr, tr, q, nodes), d_ho_var_apps(ho_apps)
45		{
46	36	NodeManager* nm = NodeManager::currentNM();
47		// process the higher-order variable applications
48	84	for (std::pair<const Node, std::vector<Node> >& as : d_ho_var_apps)
49		{
50	96	Node n = as.first;
51	48	d_ho_var_list.push_back(n);
52	96	TypeNode tn = n.getType();
53	48	Assert(tn.isFunction());
54	48	if (Trace.isOn("ho-quant-trigger"))
55		{
56		Trace("ho-quant-trigger") << " have " << as.second.size();
57		Trace("ho-quant-trigger") << " patterns with variable operator " << n
58		<< ":" << std::endl;
59		for (unsigned j = 0; j < as.second.size(); j++)
60		{
61		Trace("ho-quant-trigger") << " " << as.second[j] << std::endl;
62		}
63		}
64	48	if (d_ho_var_types.find(tn) == d_ho_var_types.end())
65		{
66	96	Trace("ho-quant-trigger") << " type " << tn
67	48	<< " needs higher-order matching." << std::endl;
68	48	d_ho_var_types.insert(tn);
69		}
70		// make the bound variable lists
71	48	d_ho_var_bvl[n] = nm->getBoundVarListForFunctionType(tn);
72	120	for (const Node& nc : d_ho_var_bvl[n])
73		{
74	72	d_ho_var_bvs[n].push_back(nc);
75		}
76		}
77	36	}
78
79	72	HigherOrderTrigger::~HigherOrderTrigger() {}
80		void HigherOrderTrigger::collectHoVarApplyTerms(
81		Node q, Node& n, std::map<Node, std::vector<Node> >& apps)
82		{
83		std::vector<Node> ns;
84		ns.push_back(n);
85		collectHoVarApplyTerms(q, ns, apps);
86		Assert(ns.size() == 1);
87		n = ns[0];
88		}
89
90	16850	void HigherOrderTrigger::collectHoVarApplyTerms(
91		Node q, std::vector<Node>& ns, std::map<Node, std::vector<Node> >& apps)
92		{
93	33700	std::unordered_map<TNode, Node> visited;
94	16850	std::unordered_map<TNode, Node>::iterator it;
95		// whether the visited node is a child of a HO_APPLY chain
96	33700	std::unordered_map<TNode, bool> withinApply;
97	33700	std::vector<TNode> visit;
98	33700	TNode cur;
99	35201	for (unsigned i = 0, size = ns.size(); i < size; i++)
100		{
101	18351	visit.push_back(ns[i]);
102	18351	withinApply[ns[i]] = false;
103	201133	do
104		{
105	219484	cur = visit.back();
106	219484	visit.pop_back();
107
108	219484	it = visited.find(cur);
109	219484	if (it == visited.end())
110		{
111		// do not look in nested quantifiers
112	107800	if (cur.getKind() == FORALL)
113		{
114		visited[cur] = cur;
115		}
116		else
117		{
118	107800	bool curWithinApply = withinApply[cur];
119	107800	visited[cur] = Node::null();
120	107800	visit.push_back(cur);
121	201133	for (unsigned j = 0, sizec = cur.getNumChildren(); j < sizec; j++)
122		{
123	93333	withinApply[cur[j]] = curWithinApply && j == 0;
124	93333	visit.push_back(cur[j]);
125		}
126		}
127		}
128	111684	else if (it->second.isNull())
129		{
130		// carry the conversion
131	215600	Node ret = cur;
132	107800	bool childChanged = false;
133	215600	std::vector<Node> children;
134	107800	if (cur.getMetaKind() == kind::metakind::PARAMETERIZED)
135		{
136	43188	children.push_back(cur.getOperator());
137		}
138	201133	for (const Node& nc : cur)
139		{
140	93333	it = visited.find(nc);
141	93333	Assert(it != visited.end());
142	93333	Assert(!it->second.isNull());
143	93333	childChanged = childChanged \|\| nc != it->second;
144	93333	children.push_back(it->second);
145		}
146	107800	if (childChanged)
147		{
148	40	ret = NodeManager::currentNM()->mkNode(cur.getKind(), children);
149		}
150		// now, convert and store the application
151	107800	if (!withinApply[cur])
152		{
153	215600	TNode op;
154	107800	if (ret.getKind() == kind::APPLY_UF)
155		{
156		// could be a fully applied function variable
157	36921	op = ret.getOperator();
158		}
159	70879	else if (ret.getKind() == kind::HO_APPLY)
160		{
161	113	op = ret;
162	407	while (op.getKind() == kind::HO_APPLY)
163		{
164	147	op = op[0];
165		}
166		}
167	107800	if (!op.isNull())
168		{
169	37034	if (op.getKind() == kind::INST_CONSTANT)
170		{
171	48	Assert(TermUtil::getInstConstAttr(ret) == q);
172	96	Trace("ho-quant-trigger-debug")
173	48	<< "Ho variable apply term : " << ret << " with head " << op
174	48	<< std::endl;
175	48	if (ret.getKind() == kind::APPLY_UF)
176		{
177	80	Node prev = ret;
178		// for consistency, convert to HO_APPLY if fully applied
179	40	ret = uf::TheoryUfRewriter::getHoApplyForApplyUf(ret);
180		}
181	48	apps[op].push_back(ret);
182		}
183		}
184		}
185	107800	visited[cur] = ret;
186		}
187	219484	} while (!visit.empty());
188
189		// store the conversion
190	18351	Assert(visited.find(ns[i]) != visited.end());
191	18351	ns[i] = visited[ns[i]];
192		}
193	16850	}
194
195	108	uint64_t HigherOrderTrigger::addInstantiations()
196		{
197		// call the base class implementation
198	108	uint64_t addedFoLemmas = Trigger::addInstantiations();
199		// also adds predicate lemms to force app completion
200	108	uint64_t addedHoLemmas = addHoTypeMatchPredicateLemmas();
201	108	return addedHoLemmas + addedFoLemmas;
202		}
203
204	192	bool HigherOrderTrigger::sendInstantiation(std::vector<Node>& m, InferenceId id)
205		{
206	192	if (options::hoMatching())
207		{
208		// get substitution corresponding to m
209	384	std::vector<TNode> vars;
210	384	std::vector<TNode> subs;
211	684	for (unsigned i = 0, size = d_quant[0].getNumChildren(); i < size; i++)
212		{
213	492	subs.push_back(m[i]);
214	492	vars.push_back(d_qreg.getInstantiationConstant(d_quant, i));
215		}
216
217	192	Trace("ho-unif-debug") << "Run higher-order unification..." << std::endl;
218
219		// get the substituted form of all variable-operator ho application terms
220	384	std::map<TNode, std::vector<Node> > ho_var_apps_subs;
221	432	for (std::pair<const Node, std::vector<Node> >& ha : d_ho_var_apps)
222		{
223	480	TNode var = ha.first;
224	480	for (unsigned j = 0, size = ha.second.size(); j < size; j++)
225		{
226	480	TNode app = ha.second[j];
227		Node sapp =
228	480	app.substitute(vars.begin(), vars.end(), subs.begin(), subs.end());
229	240	ho_var_apps_subs[var].push_back(sapp);
230	480	Trace("ho-unif-debug") << " app[" << var << "] : " << app << " -> "
231	240	<< sapp << std::endl;
232		}
233		}
234
235		// compute argument vectors for each variable
236	192	d_lchildren.clear();
237	192	d_arg_to_arg_rep.clear();
238	192	d_arg_vector.clear();
239	432	for (std::pair<const TNode, std::vector<Node> >& ha : ho_var_apps_subs)
240		{
241	480	TNode var = ha.first;
242	240	unsigned vnum = var.getAttribute(InstVarNumAttribute());
243	480	TNode value = m[vnum];
244	240	Trace("ho-unif-debug") << " val[" << var << "] = " << value << std::endl;
245
246	480	Trace("ho-unif-debug2") << "initialize lambda information..."
247	240	<< std::endl;
248		// initialize the lambda children
249	240	d_lchildren[vnum].push_back(value);
250		std::map<TNode, std::vector<Node> >::iterator ithb =
251	240	d_ho_var_bvs.find(var);
252	240	Assert(ithb != d_ho_var_bvs.end());
253	480	d_lchildren[vnum].insert(
254	480	d_lchildren[vnum].end(), ithb->second.begin(), ithb->second.end());
255
256	240	Trace("ho-unif-debug2") << "compute fixed arguments..." << std::endl;
257		// compute for each argument if it is only applied to a fixed value modulo
258		// equality
259	480	std::map<unsigned, Node> fixed_vals;
260	480	for (unsigned i = 0; i < ha.second.size(); i++)
261		{
262	480	std::vector<TNode> args;
263		// must substitute the operator we matched with the original
264		// higher-order variable (var) that matched it. This ensures that the
265		// argument vector (args) below is of the proper length. This handles,
266		// for example, matches like:
267		// (@ x y) with (@ (@ k1 k2) k3)
268		// where k3 but not k2 should be an argument of the match.
269	480	Node hmatch = ha.second[i];
270	240	Trace("ho-unif-debug2") << "Match is " << hmatch << std::endl;
271	240	hmatch = hmatch.substitute(value, var);
272	240	Trace("ho-unif-debug2") << "Pre-subs match is " << hmatch << std::endl;
273	480	Node f = uf::TheoryUfRewriter::decomposeHoApply(hmatch, args);
274		// Assert( f==value );
275	616	for (unsigned k = 0, size = args.size(); k < size; k++)
276		{
277		// must now subsitute back, to handle cases like
278		// (@ x y) matching (@ t (@ t s))
279		// where the above substitution would produce (@ x (@ x s)),
280		// but the argument should be (@ t s).
281	376	args[k] = args[k].substitute(var, value);
282	752	Node val = args[k];
283	376	std::map<unsigned, Node>::iterator itf = fixed_vals.find(k);
284	376	if (itf == fixed_vals.end())
285		{
286	376	fixed_vals[k] = val;
287		}
288		else if (!itf->second.isNull())
289		{
290		if (!d_qstate.areEqual(itf->second, args[k]))
291		{
292		if (!d_treg.getTermDatabase()->isEntailed(
293		itf->second.eqNode(args[k]), true))
294		{
295		fixed_vals[k] = Node::null();
296		}
297		}
298		}
299		}
300		}
301	240	if (Trace.isOn("ho-unif-debug"))
302		{
303		for (std::map<unsigned, Node>::iterator itf = fixed_vals.begin();
304		itf != fixed_vals.end();
305		++itf)
306		{
307		Trace("ho-unif-debug") << " arg[" << var << "][" << itf->first
308		<< "] : " << itf->second << std::endl;
309		}
310		}
311
312		// now construct argument vectors
313	240	Trace("ho-unif-debug2") << "compute argument vectors..." << std::endl;
314	480	std::map<Node, unsigned> arg_to_rep;
315	640	for (unsigned index = 0, size = ithb->second.size(); index < size;
316		index++)
317		{
318	800	Node bv_at_index = ithb->second[index];
319	400	std::map<unsigned, Node>::iterator itf = fixed_vals.find(index);
320	400	Trace("ho-unif-debug") << " * arg[" << var << "][" << index << "]";
321	400	if (itf != fixed_vals.end())
322		{
323	376	if (!itf->second.isNull())
324		{
325	752	Node r = d_qstate.getRepresentative(itf->second);
326	376	std::map<Node, unsigned>::iterator itfr = arg_to_rep.find(r);
327	376	if (itfr != arg_to_rep.end())
328		{
329	52	d_arg_to_arg_rep[vnum][index] = itfr->second;
330		// function applied to equivalent values at multiple arguments,
331		// can permute variables
332	52	d_arg_vector[vnum][itfr->second].push_back(bv_at_index);
333	104	Trace("ho-unif-debug") << " = { self } ++ arg[" << var << "]["
334	52	<< itfr->second << "]" << std::endl;
335		}
336		else
337		{
338	324	arg_to_rep[r] = index;
339		// function applied to single value, can either use variable or
340		// value at this argument position
341	324	d_arg_vector[vnum][index].push_back(bv_at_index);
342	324	d_arg_vector[vnum][index].push_back(itf->second);
343	324	if (!options::hoMatchingVarArgPriority())
344		{
345		std::reverse(d_arg_vector[vnum][index].begin(),
346		d_arg_vector[vnum][index].end());
347		}
348	648	Trace("ho-unif-debug") << " = { self, " << itf->second << " } "
349	324	<< std::endl;
350		}
351		}
352		else
353		{
354		// function is applied to disequal values, can only use variable at
355		// this argument position
356		d_arg_vector[vnum][index].push_back(bv_at_index);
357		Trace("ho-unif-debug") << " = { self } (disequal)" << std::endl;
358		}
359		}
360		else
361		{
362		// argument is irrelevant to matching, assume identity variable
363	24	d_arg_vector[vnum][index].push_back(bv_at_index);
364	24	Trace("ho-unif-debug") << " = { self } (irrelevant)" << std::endl;
365		}
366		}
367	240	Trace("ho-unif-debug2") << "finished." << std::endl;
368		}
369
370	192	bool ret = sendInstantiation(m, 0);
371	192	Trace("ho-unif-debug") << "Finished, success = " << ret << std::endl;
372	192	return ret;
373		}
374		else
375		{
376		// do not run higher-order matching
377		return d_qim.getInstantiate()->addInstantiation(d_quant, m, id);
378		}
379		}
380
381		// recursion depth limited by number of arguments of higher order variables
382		// occurring as pattern operators (very small)
383	906	bool HigherOrderTrigger::sendInstantiation(std::vector<Node>& m,
384		size_t var_index)
385		{
386	1812	Trace("ho-unif-debug2") << "send inst " << var_index << " / "
387	906	<< d_ho_var_list.size() << std::endl;
388	906	if (var_index == d_ho_var_list.size())
389		{
390		// we now have an instantiation to try
391	1204	return d_qim.getInstantiate()->addInstantiation(
392	602	d_quant, m, InferenceId::QUANTIFIERS_INST_E_MATCHING_HO);
393		}
394		else
395		{
396	608	Node var = d_ho_var_list[var_index];
397	304	unsigned vnum = var.getAttribute(InstVarNumAttribute());
398	304	Assert(vnum < m.size());
399	608	Node value = m[vnum];
400	304	Assert(d_lchildren[vnum][0] == value);
401	304	Assert(d_ho_var_bvl.find(var) != d_ho_var_bvl.end());
402
403		// now, recurse on arguments to enumerate equivalent matching lambda
404		// expressions
405		bool ret =
406	304	sendInstantiationArg(m, var_index, vnum, 0, d_ho_var_bvl[var], false);
407
408		// reset the value
409	304	m[vnum] = value;
410
411	304	return ret;
412		}
413		}
414
415	1272	bool HigherOrderTrigger::sendInstantiationArg(std::vector<Node>& m,
416		unsigned var_index,
417		unsigned vnum,
418		unsigned arg_index,
419		Node lbvl,
420		bool arg_changed)
421		{
422	2544	Trace("ho-unif-debug2") << "send inst arg " << arg_index << " / "
423	1272	<< lbvl.getNumChildren() << std::endl;
424	1272	if (arg_index == lbvl.getNumChildren())
425		{
426		// construct the lambda
427	714	if (arg_changed)
428		{
429	876	Trace("ho-unif-debug2")
430	438	<< " make lambda from children: " << d_lchildren[vnum] << std::endl;
431		Node body =
432	876	NodeManager::currentNM()->mkNode(kind::APPLY_UF, d_lchildren[vnum]);
433	438	Trace("ho-unif-debug2") << " got " << body << std::endl;
434	876	Node lam = NodeManager::currentNM()->mkNode(kind::LAMBDA, lbvl, body);
435	438	m[vnum] = lam;
436	438	Trace("ho-unif-debug2") << " try " << vnum << " -> " << lam << std::endl;
437		}
438	714	return sendInstantiation(m, var_index + 1);
439		}
440		else
441		{
442		std::map<unsigned, unsigned>::iterator itr =
443	558	d_arg_to_arg_rep[vnum].find(arg_index);
444		unsigned rindex =
445	558	itr != d_arg_to_arg_rep[vnum].end() ? itr->second : arg_index;
446		std::map<unsigned, std::vector<Node> >::iterator itv =
447	558	d_arg_vector[vnum].find(rindex);
448	558	Assert(itv != d_arg_vector[vnum].end());
449	1116	Node prev = lbvl[arg_index];
450	558	bool ret = false;
451		// try each argument in the vector
452	1196	for (unsigned i = 0, size = itv->second.size(); i < size; i++)
453		{
454	968	bool new_arg_changed = arg_changed \|\| prev != itv->second[i];
455	968	d_lchildren[vnum][arg_index + 1] = itv->second[i];
456	968	if (sendInstantiationArg(
457		m, var_index, vnum, arg_index + 1, lbvl, new_arg_changed))
458		{
459	330	ret = true;
460	330	break;
461		}
462		}
463		// clean up
464	558	d_lchildren[vnum][arg_index + 1] = prev;
465	558	return ret;
466		}
467		}
468
469	108	uint64_t HigherOrderTrigger::addHoTypeMatchPredicateLemmas()
470		{
471	108	if (d_ho_var_types.empty())
472		{
473		return 0;
474		}
475	108	Trace("ho-quant-trigger") << "addHoTypeMatchPredicateLemmas..." << std::endl;
476	108	uint64_t numLemmas = 0;
477		// this forces expansion of APPLY_UF terms to curried HO_APPLY chains
478	108	TermDb* tdb = d_treg.getTermDatabase();
479	108	unsigned size = tdb->getNumOperators();
480	108	NodeManager* nm = NodeManager::currentNM();
481	768	for (unsigned j = 0; j < size; j++)
482		{
483	1320	Node f = tdb->getOperator(j);
484	660	if (f.isVar())
485		{
486	1024	TypeNode tn = f.getType();
487	512	if (tn.isFunction())
488		{
489	1024	std::vector<TypeNode> argTypes = tn.getArgTypes();
490	512	Assert(argTypes.size() > 0);
491	1024	TypeNode range = tn.getRangeType();
492		// for each function type suffix of the type of f, for example if
493		// f : (Int -> (Int -> Int))
494		// we iterate with stn = (Int -> (Int -> Int)) and (Int -> Int)
495	1112	for (unsigned a = 0, arg_size = argTypes.size(); a < arg_size; a++)
496		{
497	1200	std::vector<TypeNode> sargts;
498	600	sargts.insert(sargts.begin(), argTypes.begin() + a, argTypes.end());
499	600	Assert(sargts.size() > 0);
500	1200	TypeNode stn = nm->mkFunctionType(sargts, range);
501	1200	Trace("ho-quant-trigger-debug")
502	600	<< "For " << f << ", check " << stn << "..." << std::endl;
503		// if a variable of this type occurs in this trigger
504	600	if (d_ho_var_types.find(stn) != d_ho_var_types.end())
505		{
506	536	Node u = tdb->getHoTypeMatchPredicate(tn);
507	536	Node au = nm->mkNode(kind::APPLY_UF, u, f);
508	268	if (d_qim.addPendingLemma(au,
509		InferenceId::QUANTIFIERS_HO_MATCH_PRED))
510		{
511		// this forces f to be a first-class member of the quantifier-free
512		// equality engine, which in turn forces the quantifier-free
513		// theory solver to expand it to an HO_APPLY chain.
514	116	Trace("ho-quant")
515	58	<< "Added ho match predicate lemma : " << au << std::endl;
516	58	numLemmas++;
517		}
518		}
519		}
520		}
521		}
522		}
523
524	108	return numLemmas;
525		}
526
527		} // namespace inst
528		} // namespace quantifiers
529		} // namespace theory
530	29340	} // namespace cvc5