add clause proof module, small improvements to bapa

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/smt/smt_clause_proof.h

@@ -0,0 +1,77 @@
+/*++
+Copyright (c) 2019 Microsoft Corporation
+
+Module Name:
+
+    smt_clause_proof.h
+
+Abstract:
+
+    This module tracks clausal proof objects as a trail of added and removed assumptions (input clauses)
+    theory lemmas and axioms, and lemmas produced from conflict resolution (possibly using theory propagation).
+   
+    Clausal proofs may serve a set of purposes:
+    - detailed diagnostics of general properties of the search.
+    - an interface to proof checking 
+    - an interface to replay in trusted bases
+    - an interface to proof pruning methods
+    - an interface to clausal interpolation methods.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2019-03-15
+
+Revision History:
+
+--*/
+#ifndef SMT_CLAUSE_PROOF_H_
+#define SMT_CLAUSE_PROOF_H_
+
+#include "smt/smt_theory.h"
+#include "smt/smt_clause.h"
+
+namespace smt {
+    class context;
+    class justification;
+
+    class clause_proof {
+    public:
+        enum status {
+            lemma,
+            assumption,
+            th_lemma,
+            th_assumption,
+            deleted
+        };
+    private:
+
+        struct info {
+            status          m_status;
+            expr_ref_vector m_clause;     
+            proof_ref       m_proof;
+            info(status st, expr_ref_vector& v, proof* p): m_status(st), m_clause(v), m_proof(p, m_clause.m()) {}
+        };
+        context&     ctx;
+        ast_manager& m;
+        expr_ref_vector m_lits;
+        vector<info> m_trail;
+        void update(status st, expr_ref_vector& v, proof* p);
+        void update(clause& c, status st, proof* p);
+        status kind2st(clause_kind k);
+        proof* justification2proof(justification* j);
+    public:
+        clause_proof(context& ctx);
+        void shrink(clause& c, unsigned new_size);
+        void add(literal lit, clause_kind k, justification* j);
+        void add(literal lit1, literal lit2, clause_kind k, justification* j);
+        void add(clause& c);
+        void add(unsigned n, literal const* lits, clause_kind k, justification* j);
+        void del(clause& c);
+        proof_ref get_proof();
+    };
+
+    std::ostream& operator<<(std::ostream& out, clause_proof::status st);
+};
+
+#endif /* SMT_CLAUSE_PROOF_H_ */
+