adding basic plugin

src/ast/sls/sls_basic_plugin.h

@@ -0,0 +1,61 @@
+/*++
+Copyright (c) 2020 Microsoft Corporation
+
+Module Name:
+
+    sls_basic_plugin.h
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2024-07-05
+
+--*/
+#pragma once
+
+#include "ast/sls/sls_smt.h"
+
+namespace sls {
+
+    class basic_plugin : public plugin {
+        bool_vector        m_values;
+        indexed_uint_set   m_repair_up, m_repair_roots;
+        unsigned           m_repair_down = UINT_MAX;
+        bool               m_initialized = false;
+
+        void init();
+        bool bval1(app* e) const;
+        bool bval0(expr* e) const;
+        bool repair_up(expr* e);
+        bool try_repair(app* e, unsigned i);
+        bool try_repair_and_or(app* e, unsigned i);
+        bool try_repair_not(app* e);
+        bool try_repair_eq(app* e, unsigned i);
+        bool try_repair_xor(app* e, unsigned i);
+        bool try_repair_ite(app* e, unsigned i);
+        bool try_repair_implies(app* e, unsigned i);
+        void set_value(expr* e, bool b);
+
+        void repair_down(app* e);
+        void repair_defs_and_updates();
+        void repair_literal(sat::literal lit);
+
+    public:
+        basic_plugin(context& ctx) : 
+            plugin(ctx) { 
+        }
+        ~basic_plugin() override {}
+        void init_bool_var(sat::bool_var v) override {}
+        void register_term(expr* e) override {}
+        expr_ref get_value(expr* e) override;
+        lbool check() override;
+        bool is_sat() override;
+
+        void on_rescale() override {}
+        void on_restart() override {}
+        std::ostream& display(std::ostream& out) const override;
+        void mk_model(model& mdl) override {}
+        void set_shared(expr* e) override {}
+        void set_value(expr* e, expr* v) override;
+    };
+
+}