adding pb sls

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

src/opt/pb_sls.h

@@ -0,0 +1,50 @@
+/*++
+Copyright (c) 2014 Microsoft Corporation
+
+Module Name:
+
+    pb_sls.h
+
+Abstract:
+   
+    SLS for PB optimization.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2014-03-18
+
+Notes:
+
+--*/
+#ifndef _PB_SLS_H_
+#define _PB_SLS_H_
+
+#include "pb_decl_plugin.h"
+#include "model.h"
+#include "lbool.h"
+#include "params.h"
+#include "statistics.h"
+
+namespace smt {
+
+    class pb_sls {
+        struct imp;
+        imp* m_imp;
+    public:        
+        pb_sls(ast_manager& m);        
+        ~pb_sls();
+        void add(expr* f);
+        void add(expr* f, rational const& w);
+        void init_value(expr* f, bool b);
+        lbool operator()();
+        bool get_value(expr* f);
+        void set_cancel(bool f);
+        void collect_statistics(statistics& st) const;
+        void get_model(model_ref& mdl);
+        void updt_params(params_ref& p);
+    };
+
+
+};
+
+#endif