1 files changed, 109 insertions, 0 deletions
diff --git a/src/theory/difficulty_manager.cpp b/src/theory/difficulty_manager.cpp
new file mode 100644
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+++ b/src/theory/difficulty_manager.cpp
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+/******************************************************************************
+ * Top contributors (to current version):
+ *   Andrew Reynolds
+ *
+ * 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.
+ * ****************************************************************************
+ *
+ * Difficulty manager.
+ */
+
+#include "theory/difficulty_manager.h"
+
+#include "options/smt_options.h"
+#include "smt/env.h"
+#include "theory/theory_model.h"
+#include "util/rational.h"
+
+namespace cvc5 {
+namespace theory {
+
+DifficultyManager::DifficultyManager(context::Context* c, Valuation val)
+    : d_val(val), d_dfmap(c)
+{
+}
+
+void DifficultyManager::getDifficultyMap(std::map<Node, Node>& dmap)
+{
+  NodeManager* nm = NodeManager::currentNM();
+  for (const std::pair<const Node, uint64_t> p : d_dfmap)
+  {
+    dmap[p.first] = nm->mkConst(Rational(p.second));
+  }
+}
+
+void DifficultyManager::notifyLemma(const std::map<TNode, TNode>& rse, Node n)
+{
+  if (options::difficultyMode() != options::DifficultyMode::LEMMA_LITERAL)
+  {
+    return;
+  }
+  Trace("diff-man") << "notifyLemma: " << n << std::endl;
+  Kind nk = n.getKind();
+  // for lemma (or a_1 ... a_n), if a_i is a literal that is not true in the
+  // valuation, then we increment the difficulty of that assertion
+  std::vector<TNode> litsToCheck;
+  if (nk == kind::OR)
+  {
+    litsToCheck.insert(litsToCheck.end(), n.begin(), n.end());
+  }
+  else if (nk == kind::IMPLIES)
+  {
+    litsToCheck.push_back(n[0].negate());
+    litsToCheck.push_back(n[1]);
+  }
+  else
+  {
+    litsToCheck.push_back(n);
+  }
+  std::map<TNode, TNode>::const_iterator it;
+  for (TNode nc : litsToCheck)
+  {
+    bool pol = nc.getKind() != kind::NOT;
+    TNode atom = pol ? nc : nc[0];
+    it = rse.find(atom);
+    if (it != rse.end())
+    {
+      incrementDifficulty(it->second);
+    }
+  }
+}
+
+void DifficultyManager::notifyCandidateModel(const NodeList& input,
+                                             TheoryModel* m)
+{
+  if (options::difficultyMode() != options::DifficultyMode::MODEL_CHECK)
+  {
+    return;
+  }
+  Trace("diff-man") << "DifficultyManager::notifyCandidateModel, #input="
+                    << input.size() << std::endl;
+  for (const Node& a : input)
+  {
+    // should have miniscoped the assertions upstream
+    Assert(a.getKind() != kind::AND);
+    // check if each input is satisfied
+    Node av = m->getValue(a);
+    if (av.isConst() && av.getConst<bool>())
+    {
+      continue;
+    }
+    Trace("diff-man") << "  not true: " << a << std::endl;
+    // not satisfied, increment counter
+    incrementDifficulty(a);
+  }
+  Trace("diff-man") << std::endl;
+}
+void DifficultyManager::incrementDifficulty(TNode a, uint64_t amount)
+{
+  Assert(a.getType().isBoolean());
+  d_dfmap[a] = d_dfmap[a] + amount;
+}
+
+}  // namespace theory
+}  // namespace cvc5