add tabulation/subsumption engine

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

src/muz_qe/tab_context.h

@@ -0,0 +1,45 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    tab_context.h
+
+Abstract:
+
+    Tabulation/subsumption/cyclic proof context.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2013-01-15
+
+Revision History:
+
+--*/
+#ifndef _TAB_CONTEXT_H_
+#define _TAB_CONTEXT_H_
+
+#include "ast.h"
+#include "lbool.h"
+#include "statistics.h"
+
+namespace datalog {
+    class context;
+
+    class tab {
+        class imp;
+        imp* m_imp;
+    public:
+        tab(context& ctx);
+        ~tab();
+        lbool query(expr* query);
+        void cancel();
+        void cleanup();
+        void reset_statistics();
+        void collect_statistics(statistics& st) const;
+        void display_certificate(std::ostream& out) const;        
+        expr_ref get_answer();
+    };
+};
+
+#endif