adding dt-solver (#4739)

* adding dt-solver

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

* dt

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

* move mbp to self-contained module

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

* files

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

* Create CMakeLists.txt

* dt

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

* rename to bool_var2expr to indicate type class

* mbp

* na

src/ast/is_variable_test.h

@@ -0,0 +1,61 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    qe_vartest.h
+
+Abstract:
+
+    Utilities for quantifiers.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2013-08-28
+
+Revision History:
+
+--*/
+#pragma once
+
+#include "ast/ast.h"
+#include "util/uint_set.h"
+
+class is_variable_proc : public std::unary_function<expr*,bool> {
+public:
+    virtual bool operator()(const expr* e) const = 0;
+};
+
+class is_variable_test : public is_variable_proc {
+    enum is_var_kind { BY_VAR_SET, BY_VAR_SET_COMPLEMENT, BY_NUM_DECLS };
+    uint_set m_var_set;
+    unsigned m_num_decls;
+    is_var_kind m_var_kind;
+public:
+    is_variable_test(uint_set const& vars, bool index_of_bound) :
+        m_var_set(vars),
+        m_num_decls(0),
+        m_var_kind(index_of_bound?BY_VAR_SET:BY_VAR_SET_COMPLEMENT) {}
+
+    is_variable_test(unsigned num_decls) :
+        m_num_decls(num_decls),
+        m_var_kind(BY_NUM_DECLS) {}
+
+    bool operator()(const expr* e) const override {
+        if (!is_var(e)) {
+            return false;
+        }
+        unsigned idx = to_var(e)->get_idx();
+        switch(m_var_kind) {
+        case BY_VAR_SET:
+            return m_var_set.contains(idx);
+        case BY_VAR_SET_COMPLEMENT:
+            return !m_var_set.contains(idx);
+        case BY_NUM_DECLS:
+            return idx < m_num_decls;
+        }
+        UNREACHABLE();
+        return false;
+    }
+};
+