Z3 sources

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

lib/distribute_forall.h

@@ -0,0 +1,82 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    distribute_forall.h
+
+Abstract:
+
+    <abstract>
+
+Author:
+
+    Leonardo de Moura (leonardo) 2010-04-02.
+
+Revision History:
+
+    Christoph Wintersteiger 2010-04-06: Added implementation
+
+--*/
+#ifndef _DISTRIBUTE_FORALL_H_
+#define _DISTRIBUTE_FORALL_H_
+
+#include"ast.h"
+#include"basic_simplifier_plugin.h"
+#include"act_cache.h"
+
+/**
+   \brief Apply the following transformation
+   (forall X (and F1 ... Fn))
+   -->
+   (and (forall X F1) ... (forall X Fn))
+
+   The actual transformation is slightly different since the "and" connective is eliminated and
+   replaced with a "not or".
+   So, the actual transformation is:
+
+   (forall X (not (or F1 ... Fn)))
+   -->
+   (not (or (not (forall X (not F1)))
+            ...
+            (not (forall X (not Fn)))))
+
+
+   The implementation uses the visit_children/reduce1 idiom. A cache is used as usual.   
+*/
+class distribute_forall {
+    typedef act_cache expr_map;
+    ast_manager &             m_manager;
+    basic_simplifier_plugin & m_bsimp; // useful for constructing formulas and/or/not in simplified form.
+    ptr_vector<expr>          m_todo;
+    expr_map                  m_cache;
+    ptr_vector<expr>          m_new_args;
+    // The new expressions are stored in a mapping that increments their reference counter. So, we do not need to store them in
+    // m_new_exprs
+    // expr_ref_vector  m_new_exprs;
+
+
+public:
+    distribute_forall(ast_manager & m, basic_simplifier_plugin & p);
+
+    /**
+       \brief Apply the distribute_forall transformation (when possible) to all universal quantifiers in \c f.
+       Store the result in \c result.
+    */
+    void operator()(expr * f, expr_ref & result);
+
+protected:
+    inline void visit(expr * n, bool & visited);
+    bool visit_children(expr * n);
+    void reduce1(expr * n);
+    void reduce1_quantifier(quantifier * q);
+    void reduce1_app(app * a);
+
+    expr * get_cached(expr * n) const;
+    bool is_cached(expr * n) const {  return get_cached(n) != 0; }
+    void cache_result(expr * n, expr * r);
+    void reset_cache() { m_cache.reset(); }
+    void flush_cache() { m_cache.cleanup(); }
+};
+
+#endif /* _DISTRIBUTE_FORALL_H_ */