Removes old proof code (#4964)

This deletes much of the old proof code. Basically everything but the minimal necessary infra-structure for producing unsat cores. That includes dependency tracking in preprocessing, the prop engine proof and the unsat core computation code in the old proof manager. These should also go once we fully integrate into master the new proof infrastructure.

It also cleans interfaces that were using old-proof-code-specific constructs (such as LemmaProofRecipe). When possible or when it made sense standalone local proof production code was kept, but deactivated (such is in the equality engine and in the arithmetic solver).

1 files changed, 11 insertions, 123 deletions

diff --git a/src/proof/cnf_proof.h b/src/proof/cnf_proof.h
index 56993583e..e437ef722 100644
--- a/src/proof/cnf_proof.h
+++ b/src/proof/cnf_proof.h
@@ -27,10 +27,8 @@
 
 #include "context/cdhashmap.h"
 #include "proof/clause_id.h"
-#include "proof/lemma_proof.h"
 #include "proof/sat_proof.h"
 #include "util/maybe.h"
-#include "util/proof.h"
 
 namespace CVC4 {
 namespace prop {
@@ -44,11 +42,11 @@ typedef std::unordered_map<Node, Node, NodeHashFunction> NodeToNode;
 typedef std::unordered_set<ClauseId> ClauseIdSet;
 
 typedef context::CDHashMap<ClauseId, Node> ClauseIdToNode;
-typedef context::CDHashMap<Node, ProofRule, NodeHashFunction> NodeToProofRule;
-typedef std::map<std::set<Node>, LemmaProofRecipe> LemmaToRecipe;
 typedef std::pair<Node, Node> NodePair;
 typedef std::set<NodePair> NodePairSet;
 
+typedef std::unordered_set<Node, NodeHashFunction> NodeSet;
+
 class CnfProof {
 protected:
   CVC4::prop::CnfStream* d_cnfStream;
@@ -56,23 +54,9 @@ protected:
   /** Map from ClauseId to the assertion that lead to adding this clause **/
   ClauseIdToNode d_clauseToAssertion;
 
-  /** Map from assertion to reason for adding assertion  **/
-  NodeToProofRule d_assertionToProofRule;
-
-  /** Map from lemma to the recipe for proving it **/
-  LemmaToRecipe d_lemmaToProofRecipe;
-
-  /** Top of stack is assertion currently being converted to CNF **/
-  std::vector<Node> d_currentAssertionStack;
-
-  /** Top of stack is top-level fact currently being converted to CNF **/
-  std::vector<Node> d_currentDefinitionStack;
-
-  /** Map from ClauseId to the top-level fact that lead to adding this clause **/
-  ClauseIdToNode d_clauseToDefinition;
-
-  /** Top-level facts that follow from assertions during convertAndAssert **/
-  NodeSet d_definitions;
+  /** Top of stack is assertion currently being converted to CNF. Also saves
+   * whether it is input (rather than a lemma). **/
+  std::vector<std::pair<Node, bool>> d_currentAssertionStack;
 
   /** Map from top-level fact to facts/assertion that it follows from **/
   NodeToNode d_cnfDeps;
@@ -84,132 +68,36 @@ protected:
   // The clause ID of the unit clause defining the false SAT literal.
   ClauseId d_falseUnitClause;
 
-  bool isDefinition(Node node);
-
-  Node getDefinitionForClause(ClauseId clause);
-
   std::string d_name;
 public:
   CnfProof(CVC4::prop::CnfStream* cnfStream,
            context::Context* ctx,
            const std::string& name);
-
-
-  Node getAtom(prop::SatVariable var);
-  prop::SatLiteral getLiteral(TNode node);
-  bool hasLiteral(TNode node);
-  void ensureLiteral(TNode node, bool noPreregistration = false);
-
-  void collectAtoms(const prop::SatClause* clause,
-                    std::set<Node>& atoms);
-  void collectAtomsForClauses(const IdToSatClause& clauses,
-                              std::set<Node>& atoms);
-  void collectAtomsAndRewritesForLemmas(const IdToSatClause& lemmaClauses,
-                                        std::set<Node>& atoms,
-                                        NodePairSet& rewrites);
-  void collectAssertionsForClauses(const IdToSatClause& clauses,
-                                   NodeSet& assertions);
+  ~CnfProof();
 
   /** Methods for logging what the CnfStream does **/
   // map the clause back to the current assertion where it came from
-  // if it is an explanation, it does not have a CNF proof since it is
-  // already in CNF
-  void registerConvertedClause(ClauseId clause, bool explanation=false);
-
-  // The CNF proof has a special relationship to true and false.
-  // In particular, it need to know the identity of clauses defining
-  // canonical true and false literals in the underlying SAT solver.
-  void registerTrueUnitClause(ClauseId clauseId);
-  void registerFalseUnitClause(ClauseId clauseId);
-  inline ClauseId getTrueUnitClause() { return d_trueUnitClause; };
-  inline ClauseId getFalseUnitClause() { return d_falseUnitClause; };
-
-  /** Clause is one of the clauses defining the node expression*/
-  void setClauseDefinition(ClauseId clause, Node node);
+  void registerConvertedClause(ClauseId clause);
 
   /** Clause is one of the clauses defining top-level assertion node*/
   void setClauseAssertion(ClauseId clause, Node node);
 
-  void registerAssertion(Node assertion, ProofRule reason);
-  void setCnfDependence(Node from, Node to);
-
-  void pushCurrentAssertion(Node assertion); // the current assertion being converted
+  /** Current assertion being converted and whether it is an input (rather than
+   * a lemma) */
+  void pushCurrentAssertion(Node assertion, bool isInput = false);
   void popCurrentAssertion();
   Node getCurrentAssertion();
-
-  void pushCurrentDefinition(Node assertion); // the current Tseitin definition being converted
-  void popCurrentDefinition();
-  Node getCurrentDefinition();
+  bool getCurrentAssertionKind();
 
   /**
    * Checks whether the assertion stack is empty.
    */
   bool isAssertionStackEmpty() const { return d_currentAssertionStack.empty(); }
 
-  void setProofRecipe(LemmaProofRecipe* proofRecipe);
-  LemmaProofRecipe getProofRecipe(const std::set<Node> &lemma);
-  bool haveProofRecipe(const std::set<Node> &lemma);
-
   // accessors for the leaf assertions that are being converted to CNF
-  bool isAssertion(Node node);
-  ProofRule getProofRule(Node assertion);
-  ProofRule getProofRule(ClauseId clause);
   Node getAssertionForClause(ClauseId clause);
-
-  /** Virtual methods for printing things **/
-  virtual void printAtomMapping(const std::set<Node>& atoms,
-                                std::ostream& os,
-                                std::ostream& paren) = 0;
-  virtual void printAtomMapping(const std::set<Node>& atoms,
-                           std::ostream& os,
-                           std::ostream& paren,
-                           ProofLetMap &letMap) = 0;
-
-  // Detects whether a clause has x v ~x for some x
-  // If so, returns the positive occurence's idx first, then the negative's
-  static Maybe<std::pair<size_t, size_t>> detectTrivialTautology(
-      const prop::SatClause& clause);
-  virtual void printClause(const prop::SatClause& clause,
-                           std::ostream& os,
-                           std::ostream& paren) = 0;
-  virtual void printCnfProofForClause(ClauseId id,
-                                      const prop::SatClause* clause,
-                                      std::ostream& os,
-                                      std::ostream& paren) = 0;
-  virtual ~CnfProof();
 };/* class CnfProof */
 
-class LFSCCnfProof : public CnfProof {
-  Node clauseToNode( const prop::SatClause& clause,
-                     std::map<Node, unsigned>& childIndex,
-                     std::map<Node, bool>& childPol );
-  bool printProofTopLevel(Node e, std::ostream& out);
-public:
-  LFSCCnfProof(CVC4::prop::CnfStream* cnfStream,
-               context::Context* ctx,
-               const std::string& name)
-    : CnfProof(cnfStream, ctx, name)
-  {}
-  ~LFSCCnfProof() {}
-
-  void printAtomMapping(const std::set<Node>& atoms,
-                        std::ostream& os,
-                        std::ostream& paren) override;
-
-  void printAtomMapping(const std::set<Node>& atoms,
-                        std::ostream& os,
-                        std::ostream& paren,
-                        ProofLetMap& letMap) override;
-
-  void printClause(const prop::SatClause& clause,
-                   std::ostream& os,
-                   std::ostream& paren) override;
-  void printCnfProofForClause(ClauseId id,
-                              const prop::SatClause* clause,
-                              std::ostream& os,
-                              std::ostream& paren) override;
-};/* class LFSCCnfProof */
-
 } /* CVC4 namespace */
 
 #endif /* CVC4__CNF_PROOF_H */