Z3 sources

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

lib/var_subst.h

@@ -0,0 +1,78 @@
+/*++
+Copyright (c) 2007 Microsoft Corporation
+
+Module Name:
+
+    var_subst.h
+
+Abstract:
+
+    Variable substitution.
+
+Author:
+
+    Leonardo (leonardo) 2008-01-10
+
+Notes:
+
+--*/
+#ifndef _VAR_SUBST_H_
+#define _VAR_SUBST_H_
+
+#include"rewriter.h"
+
+/**
+   \brief Alias for var_shifter class.
+*/
+typedef var_shifter shift_vars;
+
+/**
+   \brief Variable substitution functor. It substitutes variables by expressions.
+   The expressions may contain variables.
+*/
+class var_subst { 
+    beta_reducer   m_reducer;
+    bool           m_std_order;
+public:
+    var_subst(ast_manager & m, bool std_order = true):m_reducer(m), m_std_order(std_order) {}
+    bool std_order() const { return m_std_order; }
+
+    /**
+       When std_order() == true, 
+       I'm using the same standard used in quantifier instantiation.
+       (VAR 0) is stored in the last position of the array.
+       ...
+       (VAR (num_args - 1)) is stored in the first position of the array.
+
+       Otherwise, (VAR 0) is stored in the first position, (VAR 1) in the second, and so on.
+    */
+    void operator()(expr * n, unsigned num_args, expr * const * args, expr_ref & result);
+    void reset() { m_reducer.reset(); }
+};
+
+/**
+   \brief Eliminate the unused variables from \c q. Store the result in \c r.
+*/
+void elim_unused_vars(ast_manager & m, quantifier * q, expr_ref & r);
+
+/**
+   \brief Instantiate quantifier q using the given exprs.
+   The vector exprs should contain at least q->get_num_decls() expressions.
+
+   I'm using the same standard used in quantifier instantiation.
+   (VAR 0) is stored in the last position of the array.
+   ...
+   (VAR (q->get_num_decls() - 1)) is stored in the first position of the array.
+*/
+void instantiate(ast_manager & m, quantifier * q, expr * const * exprs, expr_ref & result);
+
+/**
+   \brief Enumerate set of free variables in expression.
+
+   Return the sorts of the free variables.
+*/
+void get_free_vars(expr* e, ptr_vector<sort>& sorts);
+
+#endif
+
+