add anf

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

src/sat/sat_anf_simplifier.h

@@ -0,0 +1,75 @@
+/*++
+  Copyright (c) 2020 Microsoft Corporation
+
+  Module Name:
+
+   sat_anf_simplifier.h
+
+  Abstract:
+   
+    Simplification based on ANF format.
+
+  Author:
+
+    Nikolaj Bjorner 2020-01-02
+
+  Notes:
+  
+
+  --*/
+#pragma once;
+
+#include "util/params.h"
+#include "util/statistics.h"
+#include "sat/sat_clause.h"
+#include "sat/sat_types.h"
+#include "sat/sat_solver.h"
+
+namespace sat {
+
+    class pdd_solver;
+
+    class anf_simplifier {
+    public:
+        struct config {
+            unsigned m_max_clause_size;
+            unsigned m_max_clauses;
+            config():
+                m_max_clause_size(10),
+                m_max_clauses(10000)
+            {}
+        };
+    private:
+        solver& s;
+        config  m_config;
+        svector<bool> m_relevant;
+
+        void collect_clauses(clause_vector & clauses, svector<solver::bin_clause>& bins);
+        void collect_xors(vector<literal_vector>& xors);
+        void configure_solver(pdd_solver& ps);
+        void add_clause(clause const& c, pdd_solver& ps);
+        void add_bin(solver::bin_clause const& b, pdd_solver& ps);
+        void add_xor(literal_vector const& x, pdd_solver& ps);
+
+        bool is_pre_satisfied(clause const& c);
+        bool is_pre_satisfied(solver::bin_clause const& b);
+        bool is_too_large(clause const& c) { return c.size() > m_config.m_max_clause_size; }
+        bool has_relevant_var(clause const& c);
+        bool has_relevant_var(solver::bin_clause const& b);
+        bool is_relevant(literal l) { return is_relevant(l.var()); }
+        bool is_relevant(bool_var v) { return m_relevant[v]; }
+        bool phase_is_true(literal l);
+
+        void set_relevant(solver::bin_clause const& b);
+        void set_relevant(clause const& c);
+        void set_relevant(literal l) { set_relevant(l.var()); }
+        void set_relevant(bool_var v) { m_relevant[v] = true; }
+
+    public:
+        anf_simplifier(solver& s) : s(s) {}
+        ~anf_simplifier() {}
+        
+        void operator()();
+        void set(config const& cfg) { m_config = cfg; }
+    };
+}