Head

GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/proof/proof_node_manager.cpp	Lines:	152	188	80.9 %
Date:	2021-08-01	Branches:	258	810	31.9 %


/******************************************************************************
 * 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);
}

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";
  Node res = checkInternal(id, children, args, expected);
  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;
  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::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)
        {
          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->getResult() != pnr->getResult())
  {
    return false;
  }
  // can shortcut re-check of rule
  return updateNodeInternal(
      pn, pnr->getRule(), pnr->getChildren(), pnr->getArguments(), false);
}

Node ProofNodeManager::checkInternal(
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args,
    Node expected)
{
  Node res;
  if (d_checker)
  {
    // check with the checker, which takes expected as argument
    res = d_checker->check(id, children, args, expected);
    Assert(!res.isNull())
        << "ProofNodeManager::checkInternal: failed to check proof";
  }
  else
  {
    // otherwise we trust the expected value, if it exists
    Assert(!expected.isNull()) << "ProofNodeManager::checkInternal: no checker "
                                  "or expected value provided";
    res = expected;
  }
  return res;
}

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

std::shared_ptr<ProofNode> ProofNodeManager::clone(
    std::shared_ptr<ProofNode> pn)
{
  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());
        Assert(it->second != nullptr);
        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;
    }
  }
  Assert(visited.find(orig) != visited.end());
  return visited[orig];
}

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::proofEagerChecking())
  {
    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
    Node res = checkInternal(id, children, args, pn->d_proven);
    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);
  }

  // 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	3756	ProofNodeManager::ProofNodeManager(ProofChecker* pc) : d_checker(pc)
32		{
33	3756	d_true = NodeManager::currentNM()->mkConst(true);
34	3756	}
35
36	19773925	std::shared_ptr<ProofNode> ProofNodeManager::mkNode(
37		PfRule id,
38		const std::vector<std::shared_ptr<ProofNode>>& children,
39		const std::vector<Node>& args,
40		Node expected)
41		{
42	39547850	Trace("pnm") << "ProofNodeManager::mkNode " << id << " {" << expected.getId()
43	19773925	<< "} " << expected << "\n";
44	39547850	Node res = checkInternal(id, children, args, expected);
45	19773925	if (res.isNull())
46		{
47		// if it was invalid, then we return the null node
48		return nullptr;
49		}
50		// otherwise construct the proof node and set its proven field
51		std::shared_ptr<ProofNode> pn =
52	39547850	std::make_shared<ProofNode>(id, children, args);
53	19773925	pn->d_proven = res;
54	19773925	return pn;
55		}
56
57	9799756	std::shared_ptr<ProofNode> ProofNodeManager::mkAssume(Node fact)
58		{
59	9799756	Assert(!fact.isNull());
60	9799756	Assert(fact.getType().isBoolean());
61	9799756	return mkNode(PfRule::ASSUME, {}, {fact}, fact);
62		}
63
64	363	std::shared_ptr<ProofNode> ProofNodeManager::mkTrans(
65		const std::vector<std::shared_ptr<ProofNode>>& children, Node expected)
66		{
67	363	Assert(!children.empty());
68	363	if (children.size() == 1)
69		{
70		Assert(expected.isNull() \|\| children[0]->getResult() == expected);
71		return children[0];
72		}
73	363	return mkNode(PfRule::TRANS, children, {}, expected);
74		}
75
76	167778	std::shared_ptr<ProofNode> ProofNodeManager::mkScope(
77		std::shared_ptr<ProofNode> pf,
78		std::vector<Node>& assumps,
79		bool ensureClosed,
80		bool doMinimize,
81		Node expected)
82		{
83	167778	if (!ensureClosed)
84		{
85	51202	return mkNode(PfRule::SCOPE, {pf}, assumps, expected);
86		}
87	116576	Trace("pnm-scope") << "ProofNodeManager::mkScope " << assumps << std::endl;
88		// we first ensure the assumptions are flattened
89	233152	std::unordered_set<Node> ac{assumps.begin(), assumps.end()};
90		// map from the rewritten form of assumptions to the original. This is only
91		// computed in the rare case when we need rewriting to match the
92		// assumptions. An example of this is for Boolean constant equalities in
93		// scoped proofs from the proof equality engine.
94	233152	std::unordered_map<Node, Node> acr;
95		// whether we have compute the map above
96	116576	bool computedAcr = false;
97
98		// The free assumptions of the proof
99	233152	std::map<Node, std::vector<std::shared_ptr<ProofNode>>> famap;
100	116576	expr::getFreeAssumptionsMap(pf, famap);
101	233152	std::unordered_set<Node> acu;
102	516870	for (const std::pair<const Node, std::vector<std::shared_ptr<ProofNode>>>&
103	116576	fa : famap)
104		{
105	1033740	Node a = fa.first;
106	910375	if (ac.find(a) != ac.end())
107		{
108		// already covered by an assumption
109	393505	acu.insert(a);
110	393505	continue;
111		}
112		// trivial assumption
113	123365	if (a == d_true)
114		{
115	6	Trace("pnm-scope") << "- justify trivial True assumption\n";
116	12	for (std::shared_ptr<ProofNode> pfs : fa.second)
117		{
118	6	Assert(pfs->getResult() == a);
119	6	updateNode(pfs.get(), PfRule::MACRO_SR_PRED_INTRO, {}, {a});
120		}
121	6	Trace("pnm-scope") << "...finished" << std::endl;
122	6	acu.insert(a);
123	6	continue;
124		}
125	123359	Trace("pnm-scope") << "- try matching free assumption " << a << "\n";
126		// otherwise it may be due to symmetry?
127	246718	Node aeqSym = CDProof::getSymmFact(a);
128	123359	Trace("pnm-scope") << " - try sym " << aeqSym << "\n";
129	246718	Node aMatch;
130	123359	if (!aeqSym.isNull() && ac.count(aeqSym))
131		{
132	245484	Trace("pnm-scope") << "- reorient assumption " << aeqSym << " via " << a
133	245484	<< " for " << fa.second.size() << " proof nodes"
134	122742	<< std::endl;
135	122742	aMatch = aeqSym;
136		}
137		else
138		{
139		// Otherwise, may be derivable by rewriting. Note this is used in
140		// ensuring that proofs from the proof equality engine that involve
141		// equality with Boolean constants are closed.
142	617	if (!computedAcr)
143		{
144	243	computedAcr = true;
145	3508	for (const Node& acc : ac)
146		{
147	6530	Node accr = theory::Rewriter::rewrite(acc);
148	3265	if (accr != acc)
149		{
150	1262	acr[accr] = acc;
151		}
152		}
153		}
154	1234	Node ar = theory::Rewriter::rewrite(a);
155	617	std::unordered_map<Node, Node>::iterator itr = acr.find(ar);
156	617	if (itr != acr.end())
157		{
158	617	aMatch = itr->second;
159		}
160		}
161
162		// if we found a match either by symmetry or rewriting, then we connect
163		// the assumption here.
164	123359	if (!aMatch.isNull())
165		{
166	246718	std::shared_ptr<ProofNode> pfaa = mkAssume(aMatch);
167		// must correct the orientation on this leaf
168	246718	std::vector<std::shared_ptr<ProofNode>> children;
169	123359	children.push_back(pfaa);
170	246718	for (std::shared_ptr<ProofNode> pfs : fa.second)
171		{
172	123359	Assert(pfs->getResult() == a);
173		// use SYMM if possible
174	123359	if (aMatch == aeqSym)
175		{
176	122742	updateNode(pfs.get(), PfRule::SYMM, children, {});
177		}
178		else
179		{
180	617	updateNode(pfs.get(), PfRule::MACRO_SR_PRED_TRANSFORM, children, {a});
181		}
182		}
183	123359	Trace("pnm-scope") << "...finished" << std::endl;
184	123359	acu.insert(aMatch);
185	123359	continue;
186		}
187		// If we did not find a match, it is an error, since all free assumptions
188		// should be arguments to SCOPE.
189		std::stringstream ss;
190
191		bool dumpProofTraceOn = Trace.isOn("dump-proof-error");
192		if (dumpProofTraceOn)
193		{
194		ss << "The proof : " << *pf << std::endl;
195		}
196		ss << std::endl << "Free assumption: " << a << std::endl;
197		for (const Node& aprint : ac)
198		{
199		ss << "- assumption: " << aprint << std::endl;
200		}
201		if (!dumpProofTraceOn)
202		{
203		ss << "Use -t dump-proof-error for details on proof" << std::endl;
204		}
205		Unreachable() << "Generated a proof that is not closed by the scope: "
206		<< ss.str() << std::endl;
207		}
208	116576	if (acu.size() < ac.size())
209		{
210		// All assumptions should match a free assumption; if one does not, then
211		// the explanation could have been smaller.
212	43907	for (const Node& a : ac)
213		{
214	40131	if (acu.find(a) == acu.end())
215		{
216	25941	Notice() << "ProofNodeManager::mkScope: assumption " << a
217		<< " does not match a free assumption in proof" << std::endl;
218		}
219		}
220		}
221	116576	if (doMinimize && acu.size() < ac.size())
222		{
223	2757	assumps.clear();
224	2757	assumps.insert(assumps.end(), acu.begin(), acu.end());
225		}
226	113819	else if (ac.size() < assumps.size())
227		{
228		// remove duplicates to avoid redundant literals in clauses
229	167	assumps.clear();
230	167	assumps.insert(assumps.end(), ac.begin(), ac.end());
231		}
232	233152	Node minExpected;
233	116576	NodeManager* nm = NodeManager::currentNM();
234	233152	Node exp;
235	116576	if (assumps.empty())
236		{
237		// SCOPE with no arguments is a no-op, just return original
238	2207	return pf;
239		}
240	228738	Node conc = pf->getResult();
241	114369	exp = assumps.size() == 1 ? assumps[0] : nm->mkNode(AND, assumps);
242	114369	if (conc.isConst() && !conc.getConst<bool>())
243		{
244	40646	minExpected = exp.notNode();
245		}
246		else
247		{
248	73723	minExpected = nm->mkNode(IMPLIES, exp, conc);
249		}
250	114369	return mkNode(PfRule::SCOPE, {pf}, assumps, minExpected);
251		}
252
253	177938	bool ProofNodeManager::updateNode(
254		ProofNode* pn,
255		PfRule id,
256		const std::vector<std::shared_ptr<ProofNode>>& children,
257		const std::vector<Node>& args)
258		{
259	177938	return updateNodeInternal(pn, id, children, args, true);
260		}
261
262	2796220	bool ProofNodeManager::updateNode(ProofNode* pn, ProofNode* pnr)
263		{
264	2796220	Assert(pn != nullptr);
265	2796220	Assert(pnr != nullptr);
266	2796220	if (pn->getResult() != pnr->getResult())
267		{
268		return false;
269		}
270		// can shortcut re-check of rule
271	2796220	return updateNodeInternal(
272	2796220	pn, pnr->getRule(), pnr->getChildren(), pnr->getArguments(), false);
273		}
274
275	19951863	Node ProofNodeManager::checkInternal(
276		PfRule id,
277		const std::vector<std::shared_ptr<ProofNode>>& children,
278		const std::vector<Node>& args,
279		Node expected)
280		{
281	19951863	Node res;
282	19951863	if (d_checker)
283		{
284		// check with the checker, which takes expected as argument
285	19951863	res = d_checker->check(id, children, args, expected);
286	19951863	Assert(!res.isNull())
287		<< "ProofNodeManager::checkInternal: failed to check proof";
288		}
289		else
290		{
291		// otherwise we trust the expected value, if it exists
292		Assert(!expected.isNull()) << "ProofNodeManager::checkInternal: no checker "
293		"or expected value provided";
294		res = expected;
295		}
296	19951863	return res;
297		}
298
299	10308474	ProofChecker* ProofNodeManager::getChecker() const { return d_checker; }
300
301	54628	std::shared_ptr<ProofNode> ProofNodeManager::clone(
302		std::shared_ptr<ProofNode> pn)
303		{
304	54628	const ProofNode* orig = pn.get();
305	109256	std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>> visited;
306	54628	std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>>::iterator it;
307	109256	std::vector<const ProofNode*> visit;
308	109256	std::shared_ptr<ProofNode> cloned;
309	54628	visit.push_back(orig);
310		const ProofNode* cur;
311	4229400	while (!visit.empty())
312		{
313	2087386	cur = visit.back();
314	2087386	it = visited.find(cur);
315	2087386	if (it == visited.end())
316		{
317	948560	visited[cur] = nullptr;
318		const std::vector<std::shared_ptr<ProofNode>>& children =
319	948560	cur->getChildren();
320	2032758	for (const std::shared_ptr<ProofNode>& cp : children)
321		{
322	1084198	visit.push_back(cp.get());
323		}
324	948560	continue;
325		}
326	1138826	visit.pop_back();
327	1138826	if (it->second.get() == nullptr)
328		{
329	1897120	std::vector<std::shared_ptr<ProofNode>> cchildren;
330		const std::vector<std::shared_ptr<ProofNode>>& children =
331	948560	cur->getChildren();
332	2032758	for (const std::shared_ptr<ProofNode>& cp : children)
333		{
334	1084198	it = visited.find(cp.get());
335	1084198	Assert(it != visited.end());
336	1084198	Assert(it->second != nullptr);
337	1084198	cchildren.push_back(it->second);
338		}
339	1897120	cloned = std::make_shared<ProofNode>(
340	1897120	cur->getRule(), cchildren, cur->getArguments());
341	948560	visited[cur] = cloned;
342		// we trust the above cloning does not change what is proven
343	948560	cloned->d_proven = cur->d_proven;
344		}
345		}
346	54628	Assert(visited.find(orig) != visited.end());
347	109256	return visited[orig];
348		}
349
350	2974158	bool ProofNodeManager::updateNodeInternal(
351		ProofNode* pn,
352		PfRule id,
353		const std::vector<std::shared_ptr<ProofNode>>& children,
354		const std::vector<Node>& args,
355		bool needsCheck)
356		{
357	2974158	Assert(pn != nullptr);
358		// ---------------- check for cyclic
359	2974158	if (options::proofEagerChecking())
360		{
361		std::unordered_set<const ProofNode*> visited;
362		for (const std::shared_ptr<ProofNode>& cpc : children)
363		{
364		if (expr::containsSubproof(cpc.get(), pn, visited))
365		{
366		std::stringstream ss;
367		ss << "ProofNodeManager::updateNode: attempting to make cyclic proof! "
368		<< id << " " << pn->getResult() << ", children = " << std::endl;
369		for (const std::shared_ptr<ProofNode>& cp : children)
370		{
371		ss << " " << cp->getRule() << " " << cp->getResult() << std::endl;
372		}
373		ss << "Full children:" << std::endl;
374		for (const std::shared_ptr<ProofNode>& cp : children)
375		{
376		ss << " - ";
377		cp->printDebug(ss);
378		ss << std::endl;
379		}
380		Unreachable() << ss.str();
381		}
382		}
383		}
384		// ---------------- end check for cyclic
385
386		// should have already computed what is proven
387	2974158	Assert(!pn->d_proven.isNull())
388		<< "ProofNodeManager::updateProofNode: invalid proof provided";
389	2974158	if (needsCheck)
390		{
391		// We expect to prove the same thing as before
392	355876	Node res = checkInternal(id, children, args, pn->d_proven);
393	177938	if (res.isNull())
394		{
395		// if it was invalid, then we do not update
396		return false;
397		}
398		// proven field should already be the same as the result
399	177938	Assert(res == pn->d_proven);
400		}
401
402		// we update its value
403	2974158	pn->setValue(id, children, args);
404	2974158	return true;
405		}
406
407	29280	} // namespace cvc5