Z3 sources

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

lib/pdr_prop_solver.h

@@ -0,0 +1,125 @@
+/*++
+Copyright (c) 2011 Microsoft Corporation
+
+Module Name:
+
+    prop_solver.h
+
+Abstract:
+
+    SAT solver abstraction for PDR.
+
+Author:
+
+    Krystof Hoder (t-khoder) 2011-8-17.
+
+Revision History:
+
+--*/
+
+#ifndef _PROP_SOLVER_H_
+#define _PROP_SOLVER_H_
+
+#include <map>
+#include <string>
+#include <utility>
+#include "ast.h"
+#include "obj_hashtable.h"
+#include "smt_solver.h"
+#include "util.h"
+#include "vector.h"
+#include "pdr_manager.h"
+#include "pdr_smt_context_manager.h"
+
+namespace pdr {
+    class prop_solver {
+    private:
+        front_end_params&   m_fparams;        
+        ast_manager&        m;
+        manager&            m_pm;
+        symbol              m_name;
+        bool                m_try_minimize_core;
+        scoped_ptr<pdr::smt_context> m_ctx;
+        decl_vector         m_level_preds;      
+        app_ref_vector      m_pos_level_atoms;  // atoms used to identify level
+        app_ref_vector      m_neg_level_atoms;  // 
+        obj_hashtable<expr> m_level_atoms_set;
+        app_ref_vector      m_fresh;            // predicates for assumptions
+        func_decl_set       m_aux_symbols;      
+        bool                m_in_level;         
+        unsigned            m_current_level;    // set when m_in_level
+        
+        /** Add level atoms activating certain level into a vector */
+        void push_level_atoms(unsigned level, expr_ref_vector & tgt) const;
+        
+        void ensure_level(unsigned lvl);
+        
+        lbool check_safe_assumptions(
+            const expr_ref_vector & atoms, 
+            expr_ref_vector * core, 
+            model_ref * mdl, 
+            bool& assumes_level);
+        
+        class safe_assumptions;
+        
+    public:
+        prop_solver(pdr::manager& pm, symbol const& name);
+        
+        /** return true is s is a symbol introduced by prop_solver */
+        bool is_aux_symbol(func_decl * s) const { 
+            return 
+                m_aux_symbols.contains(s) ||
+                m_ctx->is_aux_predicate(s); 
+        }
+        
+        void add_level();
+        unsigned level_cnt() const;
+        
+        class scoped_level {
+            bool& m_lev;
+        public:
+            scoped_level(prop_solver& ps, unsigned lvl):m_lev(ps.m_in_level) { 
+                SASSERT(!m_lev); m_lev = true; ps.m_current_level = lvl; 
+            }
+                ~scoped_level() { m_lev = false; }
+        };
+        
+        void add_formula(expr * form);
+        void add_level_formula(expr * form, unsigned level);
+                
+        /**
+         * Return true iff conjunction of atoms is consistent with the current state of 
+         * the solver.
+         *
+         * If the conjunction of atoms is inconsistent with the solver state and core is non-zero,
+         * core will contain an unsatisfiable core of atoms.
+         *
+         * If the conjunction of atoms is consistent with the solver state and o_model is non-zero,
+         * o_model will contain the "o" literals true in the assignment.
+         */
+        lbool check_assumptions(
+            const expr_ref_vector & atoms, 
+            expr_ref_vector * core, model_ref * mdl, 
+            bool& assumes_level);
+        
+        lbool check_conjunction_as_assumptions(
+            expr * conj, expr_ref_vector * core, 
+            model_ref * mdl, bool& assumes_level);
+        
+        /**
+         * Like check_assumptions, except it also asserts an extra formula
+         */
+        lbool check_assumptions_and_formula(
+            const expr_ref_vector & atoms, 
+            expr * form, 
+            expr_ref_vector * core, 
+            model_ref * mdl, 
+            bool& assumes_level);
+        
+        void collect_statistics(statistics& st) const;
+        
+    };
+}
+
+
+#endif