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GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/proof/proof_node_manager.cpp	Lines:	163	218	74.8 %
Date:	2021-09-29	Branches:	249	892	27.9 %


/******************************************************************************
 * Top contributors (to current version):
 *   Andrew Reynolds, Haniel Barbosa, 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 proof node manager.
 */

#include "proof/proof_node_manager.h"

#include <sstream>

#include "options/proof_options.h"
#include "proof/proof.h"
#include "proof/proof_checker.h"
#include "proof/proof_node.h"
#include "proof/proof_node_algorithm.h"
#include "theory/rewriter.h"

using namespace cvc5::kind;

namespace cvc5 {

ProofNodeManager::ProofNodeManager(ProofChecker* pc) : d_checker(pc)
{
  d_true = NodeManager::currentNM()->mkConst(true);
  // we always allocate a proof checker, regardless of the proof checking mode
  Assert(d_checker != nullptr);
}

std::shared_ptr<ProofNode> ProofNodeManager::mkNode(
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args,
    Node expected)
{
  Trace("pnm") << "ProofNodeManager::mkNode " << id << " {" << expected.getId()
               << "} " << expected << "\n";
  bool didCheck = false;
  Node res = checkInternal(id, children, args, expected, didCheck);
  if (res.isNull())
  {
    // if it was invalid, then we return the null node
    return nullptr;
  }
  // otherwise construct the proof node and set its proven field
  std::shared_ptr<ProofNode> pn =
      std::make_shared<ProofNode>(id, children, args);
  pn->d_proven = res;
  pn->d_provenChecked = didCheck;
  return pn;
}

std::shared_ptr<ProofNode> ProofNodeManager::mkAssume(Node fact)
{
  Assert(!fact.isNull());
  Assert(fact.getType().isBoolean());
  return mkNode(PfRule::ASSUME, {}, {fact}, fact);
}

std::shared_ptr<ProofNode> ProofNodeManager::mkSymm(
    std::shared_ptr<ProofNode> child, Node expected)
{
  if (child->getRule() == PfRule::SYMM)
  {
    Assert(expected.isNull()
           || child->getChildren()[0]->getResult() == expected);
    return child->getChildren()[0];
  }
  return mkNode(PfRule::SYMM, {child}, {}, expected);
}

std::shared_ptr<ProofNode> ProofNodeManager::mkTrans(
    const std::vector<std::shared_ptr<ProofNode>>& children, Node expected)
{
  Assert(!children.empty());
  if (children.size() == 1)
  {
    Assert(expected.isNull() || children[0]->getResult() == expected);
    return children[0];
  }
  return mkNode(PfRule::TRANS, children, {}, expected);
}

std::shared_ptr<ProofNode> ProofNodeManager::mkScope(
    std::shared_ptr<ProofNode> pf,
    std::vector<Node>& assumps,
    bool ensureClosed,
    bool doMinimize,
    Node expected)
{
  if (!ensureClosed)
  {
    return mkNode(PfRule::SCOPE, {pf}, assumps, expected);
  }
  Trace("pnm-scope") << "ProofNodeManager::mkScope " << assumps << std::endl;
  // we first ensure the assumptions are flattened
  std::unordered_set<Node> ac{assumps.begin(), assumps.end()};
  // map from the rewritten form of assumptions to the original. This is only
  // computed in the rare case when we need rewriting to match the
  // assumptions. An example of this is for Boolean constant equalities in
  // scoped proofs from the proof equality engine.
  std::unordered_map<Node, Node> acr;
  // whether we have compute the map above
  bool computedAcr = false;

  // The free assumptions of the proof
  std::map<Node, std::vector<std::shared_ptr<ProofNode>>> famap;
  expr::getFreeAssumptionsMap(pf, famap);
  std::unordered_set<Node> acu;
  for (const std::pair<const Node, std::vector<std::shared_ptr<ProofNode>>>&
           fa : famap)
  {
    Node a = fa.first;
    if (ac.find(a) != ac.end())
    {
      // already covered by an assumption
      acu.insert(a);
      continue;
    }
    // trivial assumption
    if (a == d_true)
    {
      Trace("pnm-scope") << "- justify trivial True assumption\n";
      for (std::shared_ptr<ProofNode> pfs : fa.second)
      {
        Assert(pfs->getResult() == a);
        updateNode(pfs.get(), PfRule::MACRO_SR_PRED_INTRO, {}, {a});
      }
      Trace("pnm-scope") << "...finished" << std::endl;
      acu.insert(a);
      continue;
    }
    Trace("pnm-scope") << "- try matching free assumption " << a << "\n";
    // otherwise it may be due to symmetry?
    Node aeqSym = CDProof::getSymmFact(a);
    Trace("pnm-scope") << "  - try sym " << aeqSym << "\n";
    Node aMatch;
    if (!aeqSym.isNull() && ac.count(aeqSym))
    {
      Trace("pnm-scope") << "- reorient assumption " << aeqSym << " via " << a
                         << " for " << fa.second.size() << " proof nodes"
                         << std::endl;
      aMatch = aeqSym;
    }
    else
    {
      // Otherwise, may be derivable by rewriting. Note this is used in
      // ensuring that proofs from the proof equality engine that involve
      // equality with Boolean constants are closed.
      if (!computedAcr)
      {
        computedAcr = true;
        for (const Node& acc : ac)
        {
          Node accr = theory::Rewriter::rewrite(acc);
          if (accr != acc)
          {
            acr[accr] = acc;
          }
        }
      }
      Node ar = theory::Rewriter::rewrite(a);
      std::unordered_map<Node, Node>::iterator itr = acr.find(ar);
      if (itr != acr.end())
      {
        aMatch = itr->second;
      }
    }

    // if we found a match either by symmetry or rewriting, then we connect
    // the assumption here.
    if (!aMatch.isNull())
    {
      std::shared_ptr<ProofNode> pfaa = mkAssume(aMatch);
      // must correct the orientation on this leaf
      std::vector<std::shared_ptr<ProofNode>> children;
      children.push_back(pfaa);
      for (std::shared_ptr<ProofNode> pfs : fa.second)
      {
        Assert(pfs->getResult() == a);
        // use SYMM if possible
        if (aMatch == aeqSym)
        {
          if (pfaa->getRule() == PfRule::SYMM)
          {
            updateNode(pfs.get(), pfaa->getChildren()[0].get());
          }
          else
          {
            updateNode(pfs.get(), PfRule::SYMM, children, {});
          }
        }
        else
        {
          updateNode(pfs.get(), PfRule::MACRO_SR_PRED_TRANSFORM, children, {a});
        }
      }
      Trace("pnm-scope") << "...finished" << std::endl;
      acu.insert(aMatch);
      continue;
    }
    // If we did not find a match, it is an error, since all free assumptions
    // should be arguments to SCOPE.
    std::stringstream ss;

    bool dumpProofTraceOn = Trace.isOn("dump-proof-error");
    if (dumpProofTraceOn)
    {
      ss << "The proof : " << *pf << std::endl;
    }
    ss << std::endl << "Free assumption: " << a << std::endl;
    for (const Node& aprint : ac)
    {
      ss << "- assumption: " << aprint << std::endl;
    }
    if (!dumpProofTraceOn)
    {
      ss << "Use -t dump-proof-error for details on proof" << std::endl;
    }
    Unreachable() << "Generated a proof that is not closed by the scope: "
                  << ss.str() << std::endl;
  }
  if (acu.size() < ac.size())
  {
    // All assumptions should match a free assumption; if one does not, then
    // the explanation could have been smaller.
    for (const Node& a : ac)
    {
      if (acu.find(a) == acu.end())
      {
        Notice() << "ProofNodeManager::mkScope: assumption " << a
                 << " does not match a free assumption in proof" << std::endl;
      }
    }
  }
  if (doMinimize && acu.size() < ac.size())
  {
    assumps.clear();
    assumps.insert(assumps.end(), acu.begin(), acu.end());
  }
  else if (ac.size() < assumps.size())
  {
    // remove duplicates to avoid redundant literals in clauses
    assumps.clear();
    assumps.insert(assumps.end(), ac.begin(), ac.end());
  }
  Node minExpected;
  NodeManager* nm = NodeManager::currentNM();
  Node exp;
  if (assumps.empty())
  {
    // SCOPE with no arguments is a no-op, just return original
    return pf;
  }
  Node conc = pf->getResult();
  exp = assumps.size() == 1 ? assumps[0] : nm->mkNode(AND, assumps);
  if (conc.isConst() && !conc.getConst<bool>())
  {
    minExpected = exp.notNode();
  }
  else
  {
    minExpected = nm->mkNode(IMPLIES, exp, conc);
  }
  return mkNode(PfRule::SCOPE, {pf}, assumps, minExpected);
}

bool ProofNodeManager::updateNode(
    ProofNode* pn,
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args)
{
  return updateNodeInternal(pn, id, children, args, true);
}

bool ProofNodeManager::updateNode(ProofNode* pn, ProofNode* pnr)
{
  Assert(pn != nullptr);
  Assert(pnr != nullptr);
  if (pn == pnr)
  {
    // same node, no update necessary
    return true;
  }
  if (pn->getResult() != pnr->getResult())
  {
    return false;
  }
  // copy whether we did the check
  pn->d_provenChecked = pnr->d_provenChecked;
  // can shortcut re-check of rule
  return updateNodeInternal(
      pn, pnr->getRule(), pnr->getChildren(), pnr->getArguments(), false);
}

void ProofNodeManager::ensureChecked(ProofNode* pn)
{
  if (pn->d_provenChecked)
  {
    // already checked
    return;
  }
  // directly call the proof checker
  Node res = d_checker->check(pn, pn->getResult());
  pn->d_provenChecked = true;
  // should have the correct result
  Assert(res == pn->d_proven);
}

Node ProofNodeManager::checkInternal(
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args,
    Node expected,
    bool& didCheck)
{
  // if the user supplied an expected result, then we trust it if we are in
  // a proof checking mode that does not eagerly check rule applications
  if (!expected.isNull())
  {
    if (options::proofCheck() == options::ProofCheckMode::LAZY
        || options::proofCheck() == options::ProofCheckMode::NONE)
    {
      return expected;
    }
  }
  // check with the checker, which takes expected as argument
  Node res = d_checker->check(id, children, args, expected);
  didCheck = true;
  Assert(!res.isNull())
      << "ProofNodeManager::checkInternal: failed to check proof";
  return res;
}

ProofChecker* ProofNodeManager::getChecker() const { return d_checker; }

std::shared_ptr<ProofNode> ProofNodeManager::clone(
    std::shared_ptr<ProofNode> pn) const
{
  const ProofNode* orig = pn.get();
  std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>> visited;
  std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>>::iterator it;
  std::vector<const ProofNode*> visit;
  std::shared_ptr<ProofNode> cloned;
  visit.push_back(orig);
  const ProofNode* cur;
  while (!visit.empty())
  {
    cur = visit.back();
    it = visited.find(cur);
    if (it == visited.end())
    {
      visited[cur] = nullptr;
      const std::vector<std::shared_ptr<ProofNode>>& children =
          cur->getChildren();
      for (const std::shared_ptr<ProofNode>& cp : children)
      {
        visit.push_back(cp.get());
      }
      continue;
    }
    visit.pop_back();
    if (it->second.get() == nullptr)
    {
      std::vector<std::shared_ptr<ProofNode>> cchildren;
      const std::vector<std::shared_ptr<ProofNode>>& children =
          cur->getChildren();
      for (const std::shared_ptr<ProofNode>& cp : children)
      {
        it = visited.find(cp.get());
        Assert(it != visited.end());
        // if we encounter nullptr here, then this child is currently being
        // traversed at a higher level, hence this corresponds to a cyclic
        // proof.
        if (it->second == nullptr)
        {
          Unreachable() << "Cyclic proof encountered when cloning a proof node";
        }
        cchildren.push_back(it->second);
      }
      cloned = std::make_shared<ProofNode>(
          cur->getRule(), cchildren, cur->getArguments());
      visited[cur] = cloned;
      // we trust the above cloning does not change what is proven
      cloned->d_proven = cur->d_proven;
      cloned->d_provenChecked = cur->d_provenChecked;
    }
  }
  Assert(visited.find(orig) != visited.end());
  return visited[orig];
}

ProofNode* ProofNodeManager::cancelDoubleSymm(ProofNode* pn)
{
  while (pn->getRule() == PfRule::SYMM)
  {
    std::shared_ptr<ProofNode> pnc = pn->getChildren()[0];
    if (pnc->getRule() == PfRule::SYMM)
    {
      pn = pnc->getChildren()[0].get();
    }
    else
    {
      break;
    }
  }
  return pn;
}

bool ProofNodeManager::updateNodeInternal(
    ProofNode* pn,
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args,
    bool needsCheck)
{
  Assert(pn != nullptr);
  // ---------------- check for cyclic
  if (options::proofCheck() == options::ProofCheckMode::EAGER)
  {
    std::unordered_set<const ProofNode*> visited;
    for (const std::shared_ptr<ProofNode>& cpc : children)
    {
      if (expr::containsSubproof(cpc.get(), pn, visited))
      {
        std::stringstream ss;
        ss << "ProofNodeManager::updateNode: attempting to make cyclic proof! "
           << id << " " << pn->getResult() << ", children = " << std::endl;
        for (const std::shared_ptr<ProofNode>& cp : children)
        {
          ss << "  " << cp->getRule() << " " << cp->getResult() << std::endl;
        }
        ss << "Full children:" << std::endl;
        for (const std::shared_ptr<ProofNode>& cp : children)
        {
          ss << "  - ";
          cp->printDebug(ss);
          ss << std::endl;
        }
        Unreachable() << ss.str();
      }
    }
  }
  // ---------------- end check for cyclic

  // should have already computed what is proven
  Assert(!pn->d_proven.isNull())
      << "ProofNodeManager::updateProofNode: invalid proof provided";
  if (needsCheck)
  {
    // We expect to prove the same thing as before
    bool didCheck = false;
    Node res = checkInternal(id, children, args, pn->d_proven, didCheck);
    if (res.isNull())
    {
      // if it was invalid, then we do not update
      return false;
    }
    // proven field should already be the same as the result
    Assert(res == pn->d_proven);
    pn->d_provenChecked = didCheck;
  }

  // we update its value
  pn->setValue(id, children, args);
  return true;
}

}  // namespace cvc5


Generated by: GCOVR (Version 3.2)

Line	Exec	Source
1		/******************************************************************************
2		* Top contributors (to current version):
3		* Andrew Reynolds, Haniel Barbosa, 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 proof node manager.
14		*/
15
16		#include "proof/proof_node_manager.h"
17
18		#include <sstream>
19
20		#include "options/proof_options.h"
21		#include "proof/proof.h"
22		#include "proof/proof_checker.h"
23		#include "proof/proof_node.h"
24		#include "proof/proof_node_algorithm.h"
25		#include "theory/rewriter.h"
26
27		using namespace cvc5::kind;
28
29		namespace cvc5 {
30
31	143	ProofNodeManager::ProofNodeManager(ProofChecker* pc) : d_checker(pc)
32		{
33	143	d_true = NodeManager::currentNM()->mkConst(true);
34		// we always allocate a proof checker, regardless of the proof checking mode
35	143	Assert(d_checker != nullptr);
36	143	}
37
38	372461	std::shared_ptr<ProofNode> ProofNodeManager::mkNode(
39		PfRule id,
40		const std::vector<std::shared_ptr<ProofNode>>& children,
41		const std::vector<Node>& args,
42		Node expected)
43		{
44	744922	Trace("pnm") << "ProofNodeManager::mkNode " << id << " {" << expected.getId()
45	372461	<< "} " << expected << "\n";
46	372461	bool didCheck = false;
47	744922	Node res = checkInternal(id, children, args, expected, didCheck);
48	372461	if (res.isNull())
49		{
50		// if it was invalid, then we return the null node
51		return nullptr;
52		}
53		// otherwise construct the proof node and set its proven field
54		std::shared_ptr<ProofNode> pn =
55	744922	std::make_shared<ProofNode>(id, children, args);
56	372461	pn->d_proven = res;
57	372461	pn->d_provenChecked = didCheck;
58	372461	return pn;
59		}
60
61	106402	std::shared_ptr<ProofNode> ProofNodeManager::mkAssume(Node fact)
62		{
63	106402	Assert(!fact.isNull());
64	106402	Assert(fact.getType().isBoolean());
65	106402	return mkNode(PfRule::ASSUME, {}, {fact}, fact);
66		}
67
68	21836	std::shared_ptr<ProofNode> ProofNodeManager::mkSymm(
69		std::shared_ptr<ProofNode> child, Node expected)
70		{
71	21836	if (child->getRule() == PfRule::SYMM)
72		{
73	4	Assert(expected.isNull()
74		\|\| child->getChildren()[0]->getResult() == expected);
75	4	return child->getChildren()[0];
76		}
77	21832	return mkNode(PfRule::SYMM, {child}, {}, expected);
78		}
79
80	10	std::shared_ptr<ProofNode> ProofNodeManager::mkTrans(
81		const std::vector<std::shared_ptr<ProofNode>>& children, Node expected)
82		{
83	10	Assert(!children.empty());
84	10	if (children.size() == 1)
85		{
86		Assert(expected.isNull() \|\| children[0]->getResult() == expected);
87		return children[0];
88		}
89	10	return mkNode(PfRule::TRANS, children, {}, expected);
90		}
91
92	12198	std::shared_ptr<ProofNode> ProofNodeManager::mkScope(
93		std::shared_ptr<ProofNode> pf,
94		std::vector<Node>& assumps,
95		bool ensureClosed,
96		bool doMinimize,
97		Node expected)
98		{
99	12198	if (!ensureClosed)
100		{
101	4341	return mkNode(PfRule::SCOPE, {pf}, assumps, expected);
102		}
103	7857	Trace("pnm-scope") << "ProofNodeManager::mkScope " << assumps << std::endl;
104		// we first ensure the assumptions are flattened
105	15714	std::unordered_set<Node> ac{assumps.begin(), assumps.end()};
106		// map from the rewritten form of assumptions to the original. This is only
107		// computed in the rare case when we need rewriting to match the
108		// assumptions. An example of this is for Boolean constant equalities in
109		// scoped proofs from the proof equality engine.
110	15714	std::unordered_map<Node, Node> acr;
111		// whether we have compute the map above
112	7857	bool computedAcr = false;
113
114		// The free assumptions of the proof
115	15714	std::map<Node, std::vector<std::shared_ptr<ProofNode>>> famap;
116	7857	expr::getFreeAssumptionsMap(pf, famap);
117	15714	std::unordered_set<Node> acu;
118	38439	for (const std::pair<const Node, std::vector<std::shared_ptr<ProofNode>>>&
119	7857	fa : famap)
120		{
121	76878	Node a = fa.first;
122	68402	if (ac.find(a) != ac.end())
123		{
124		// already covered by an assumption
125	29963	acu.insert(a);
126	29963	continue;
127		}
128		// trivial assumption
129	8476	if (a == d_true)
130		{
131		Trace("pnm-scope") << "- justify trivial True assumption\n";
132		for (std::shared_ptr<ProofNode> pfs : fa.second)
133		{
134		Assert(pfs->getResult() == a);
135		updateNode(pfs.get(), PfRule::MACRO_SR_PRED_INTRO, {}, {a});
136		}
137		Trace("pnm-scope") << "...finished" << std::endl;
138		acu.insert(a);
139		continue;
140		}
141	8476	Trace("pnm-scope") << "- try matching free assumption " << a << "\n";
142		// otherwise it may be due to symmetry?
143	16952	Node aeqSym = CDProof::getSymmFact(a);
144	8476	Trace("pnm-scope") << " - try sym " << aeqSym << "\n";
145	16952	Node aMatch;
146	8476	if (!aeqSym.isNull() && ac.count(aeqSym))
147		{
148	16952	Trace("pnm-scope") << "- reorient assumption " << aeqSym << " via " << a
149	16952	<< " for " << fa.second.size() << " proof nodes"
150	8476	<< std::endl;
151	8476	aMatch = aeqSym;
152		}
153		else
154		{
155		// Otherwise, may be derivable by rewriting. Note this is used in
156		// ensuring that proofs from the proof equality engine that involve
157		// equality with Boolean constants are closed.
158		if (!computedAcr)
159		{
160		computedAcr = true;
161		for (const Node& acc : ac)
162		{
163		Node accr = theory::Rewriter::rewrite(acc);
164		if (accr != acc)
165		{
166		acr[accr] = acc;
167		}
168		}
169		}
170		Node ar = theory::Rewriter::rewrite(a);
171		std::unordered_map<Node, Node>::iterator itr = acr.find(ar);
172		if (itr != acr.end())
173		{
174		aMatch = itr->second;
175		}
176		}
177
178		// if we found a match either by symmetry or rewriting, then we connect
179		// the assumption here.
180	8476	if (!aMatch.isNull())
181		{
182	16952	std::shared_ptr<ProofNode> pfaa = mkAssume(aMatch);
183		// must correct the orientation on this leaf
184	16952	std::vector<std::shared_ptr<ProofNode>> children;
185	8476	children.push_back(pfaa);
186	16952	for (std::shared_ptr<ProofNode> pfs : fa.second)
187		{
188	8476	Assert(pfs->getResult() == a);
189		// use SYMM if possible
190	8476	if (aMatch == aeqSym)
191		{
192	8476	if (pfaa->getRule() == PfRule::SYMM)
193		{
194		updateNode(pfs.get(), pfaa->getChildren()[0].get());
195		}
196		else
197		{
198	8476	updateNode(pfs.get(), PfRule::SYMM, children, {});
199		}
200		}
201		else
202		{
203		updateNode(pfs.get(), PfRule::MACRO_SR_PRED_TRANSFORM, children, {a});
204		}
205		}
206	8476	Trace("pnm-scope") << "...finished" << std::endl;
207	8476	acu.insert(aMatch);
208	8476	continue;
209		}
210		// If we did not find a match, it is an error, since all free assumptions
211		// should be arguments to SCOPE.
212		std::stringstream ss;
213
214		bool dumpProofTraceOn = Trace.isOn("dump-proof-error");
215		if (dumpProofTraceOn)
216		{
217		ss << "The proof : " << *pf << std::endl;
218		}
219		ss << std::endl << "Free assumption: " << a << std::endl;
220		for (const Node& aprint : ac)
221		{
222		ss << "- assumption: " << aprint << std::endl;
223		}
224		if (!dumpProofTraceOn)
225		{
226		ss << "Use -t dump-proof-error for details on proof" << std::endl;
227		}
228		Unreachable() << "Generated a proof that is not closed by the scope: "
229		<< ss.str() << std::endl;
230		}
231	7857	if (acu.size() < ac.size())
232		{
233		// All assumptions should match a free assumption; if one does not, then
234		// the explanation could have been smaller.
235	2583	for (const Node& a : ac)
236		{
237	2460	if (acu.find(a) == acu.end())
238		{
239	1069	Notice() << "ProofNodeManager::mkScope: assumption " << a
240		<< " does not match a free assumption in proof" << std::endl;
241		}
242		}
243		}
244	7857	if (doMinimize && acu.size() < ac.size())
245		{
246	72	assumps.clear();
247	72	assumps.insert(assumps.end(), acu.begin(), acu.end());
248		}
249	7785	else if (ac.size() < assumps.size())
250		{
251		// remove duplicates to avoid redundant literals in clauses
252	449	assumps.clear();
253	449	assumps.insert(assumps.end(), ac.begin(), ac.end());
254		}
255	15714	Node minExpected;
256	7857	NodeManager* nm = NodeManager::currentNM();
257	15714	Node exp;
258	7857	if (assumps.empty())
259		{
260		// SCOPE with no arguments is a no-op, just return original
261	229	return pf;
262		}
263	15256	Node conc = pf->getResult();
264	7628	exp = assumps.size() == 1 ? assumps[0] : nm->mkNode(AND, assumps);
265	7628	if (conc.isConst() && !conc.getConst<bool>())
266		{
267	1921	minExpected = exp.notNode();
268		}
269		else
270		{
271	5707	minExpected = nm->mkNode(IMPLIES, exp, conc);
272		}
273	7628	return mkNode(PfRule::SCOPE, {pf}, assumps, minExpected);
274		}
275
276	9067	bool ProofNodeManager::updateNode(
277		ProofNode* pn,
278		PfRule id,
279		const std::vector<std::shared_ptr<ProofNode>>& children,
280		const std::vector<Node>& args)
281		{
282	9067	return updateNodeInternal(pn, id, children, args, true);
283		}
284
285	33927	bool ProofNodeManager::updateNode(ProofNode* pn, ProofNode* pnr)
286		{
287	33927	Assert(pn != nullptr);
288	33927	Assert(pnr != nullptr);
289	33927	if (pn == pnr)
290		{
291		// same node, no update necessary
292		return true;
293		}
294	33927	if (pn->getResult() != pnr->getResult())
295		{
296		return false;
297		}
298		// copy whether we did the check
299	33927	pn->d_provenChecked = pnr->d_provenChecked;
300		// can shortcut re-check of rule
301	33927	return updateNodeInternal(
302	33927	pn, pnr->getRule(), pnr->getChildren(), pnr->getArguments(), false);
303		}
304
305	3618	void ProofNodeManager::ensureChecked(ProofNode* pn)
306		{
307	3618	if (pn->d_provenChecked)
308		{
309		// already checked
310	1467	return;
311		}
312		// directly call the proof checker
313	4302	Node res = d_checker->check(pn, pn->getResult());
314	2151	pn->d_provenChecked = true;
315		// should have the correct result
316	2151	Assert(res == pn->d_proven);
317		}
318
319	381528	Node ProofNodeManager::checkInternal(
320		PfRule id,
321		const std::vector<std::shared_ptr<ProofNode>>& children,
322		const std::vector<Node>& args,
323		Node expected,
324		bool& didCheck)
325		{
326		// if the user supplied an expected result, then we trust it if we are in
327		// a proof checking mode that does not eagerly check rule applications
328	381528	if (!expected.isNull())
329		{
330	545066	if (options::proofCheck() == options::ProofCheckMode::LAZY
331	272533	\|\| options::proofCheck() == options::ProofCheckMode::NONE)
332		{
333	272533	return expected;
334		}
335		}
336		// check with the checker, which takes expected as argument
337	217990	Node res = d_checker->check(id, children, args, expected);
338	108995	didCheck = true;
339	108995	Assert(!res.isNull())
340		<< "ProofNodeManager::checkInternal: failed to check proof";
341	108995	return res;
342		}
343
344	10956	ProofChecker* ProofNodeManager::getChecker() const { return d_checker; }
345
346	5461	std::shared_ptr<ProofNode> ProofNodeManager::clone(
347		std::shared_ptr<ProofNode> pn) const
348		{
349	5461	const ProofNode* orig = pn.get();
350	10922	std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>> visited;
351	5461	std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>>::iterator it;
352	10922	std::vector<const ProofNode*> visit;
353	10922	std::shared_ptr<ProofNode> cloned;
354	5461	visit.push_back(orig);
355		const ProofNode* cur;
356	277825	while (!visit.empty())
357		{
358	136182	cur = visit.back();
359	136182	it = visited.find(cur);
360	136182	if (it == visited.end())
361		{
362	67255	visited[cur] = nullptr;
363		const std::vector<std::shared_ptr<ProofNode>>& children =
364	67255	cur->getChildren();
365	130721	for (const std::shared_ptr<ProofNode>& cp : children)
366		{
367	63466	visit.push_back(cp.get());
368		}
369	67255	continue;
370		}
371	68927	visit.pop_back();
372	68927	if (it->second.get() == nullptr)
373		{
374	134510	std::vector<std::shared_ptr<ProofNode>> cchildren;
375		const std::vector<std::shared_ptr<ProofNode>>& children =
376	67255	cur->getChildren();
377	130721	for (const std::shared_ptr<ProofNode>& cp : children)
378		{
379	63466	it = visited.find(cp.get());
380	63466	Assert(it != visited.end());
381		// if we encounter nullptr here, then this child is currently being
382		// traversed at a higher level, hence this corresponds to a cyclic
383		// proof.
384	63466	if (it->second == nullptr)
385		{
386		Unreachable() << "Cyclic proof encountered when cloning a proof node";
387		}
388	63466	cchildren.push_back(it->second);
389		}
390	134510	cloned = std::make_shared<ProofNode>(
391	134510	cur->getRule(), cchildren, cur->getArguments());
392	67255	visited[cur] = cloned;
393		// we trust the above cloning does not change what is proven
394	67255	cloned->d_proven = cur->d_proven;
395	67255	cloned->d_provenChecked = cur->d_provenChecked;
396		}
397		}
398	5461	Assert(visited.find(orig) != visited.end());
399	10922	return visited[orig];
400		}
401
402	5673	ProofNode* ProofNodeManager::cancelDoubleSymm(ProofNode* pn)
403		{
404	5673	while (pn->getRule() == PfRule::SYMM)
405		{
406	5673	std::shared_ptr<ProofNode> pnc = pn->getChildren()[0];
407	5673	if (pnc->getRule() == PfRule::SYMM)
408		{
409		pn = pnc->getChildren()[0].get();
410		}
411		else
412		{
413	5673	break;
414		}
415		}
416	5673	return pn;
417		}
418
419	42994	bool ProofNodeManager::updateNodeInternal(
420		ProofNode* pn,
421		PfRule id,
422		const std::vector<std::shared_ptr<ProofNode>>& children,
423		const std::vector<Node>& args,
424		bool needsCheck)
425		{
426	42994	Assert(pn != nullptr);
427		// ---------------- check for cyclic
428	42994	if (options::proofCheck() == options::ProofCheckMode::EAGER)
429		{
430		std::unordered_set<const ProofNode*> visited;
431		for (const std::shared_ptr<ProofNode>& cpc : children)
432		{
433		if (expr::containsSubproof(cpc.get(), pn, visited))
434		{
435		std::stringstream ss;
436		ss << "ProofNodeManager::updateNode: attempting to make cyclic proof! "
437		<< id << " " << pn->getResult() << ", children = " << std::endl;
438		for (const std::shared_ptr<ProofNode>& cp : children)
439		{
440		ss << " " << cp->getRule() << " " << cp->getResult() << std::endl;
441		}
442		ss << "Full children:" << std::endl;
443		for (const std::shared_ptr<ProofNode>& cp : children)
444		{
445		ss << " - ";
446		cp->printDebug(ss);
447		ss << std::endl;
448		}
449		Unreachable() << ss.str();
450		}
451		}
452		}
453		// ---------------- end check for cyclic
454
455		// should have already computed what is proven
456	42994	Assert(!pn->d_proven.isNull())
457		<< "ProofNodeManager::updateProofNode: invalid proof provided";
458	42994	if (needsCheck)
459		{
460		// We expect to prove the same thing as before
461	9067	bool didCheck = false;
462	18134	Node res = checkInternal(id, children, args, pn->d_proven, didCheck);
463	9067	if (res.isNull())
464		{
465		// if it was invalid, then we do not update
466		return false;
467		}
468		// proven field should already be the same as the result
469	9067	Assert(res == pn->d_proven);
470	9067	pn->d_provenChecked = didCheck;
471		}
472
473		// we update its value
474	42994	pn->setValue(id, children, args);
475	42994	return true;
476		}
477
478	22746	} // namespace cvc5