Z3 sources

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

lib/pull_quant.h

@@ -0,0 +1,67 @@
+/*++
+Copyright (c) 2007 Microsoft Corporation
+
+Module Name:
+
+    pull_quant.h
+
+Abstract:
+
+    Pull nested quantifiers.
+
+Author:
+
+    Leonardo (leonardo) 2008-01-20
+
+Notes:
+
+--*/
+#ifndef _PULL_QUANT_H_
+#define _PULL_QUANT_H_
+
+#include"simplifier.h"
+#include"var_subst.h"
+
+/**
+   \brief Pull nested quantifiers in a formula. 
+   
+   \warning It assumes the input formula is in NNF.
+
+   \remark pull_quant(F) is a quantifier if F contains a quantifier.
+   
+   \remark If pull_quant(F) is a quantifier then its weight is 
+   Min{weight(Q') | Q' is a quantifier nested in F}
+*/
+class pull_quant : public base_simplifier {
+protected:    
+    shift_vars m_shift;
+    bool visit_children(expr * n);
+    void reduce1(expr *);
+    void reduce1_app(app * n);
+    void reduce1_quantifier(quantifier * q);
+    
+public:
+    pull_quant(ast_manager & m);
+    virtual ~pull_quant() {}
+    void operator()(expr * n, expr_ref & r, proof_ref & p);
+    void reset() { flush_cache(); }
+    void pull_quant1(func_decl * d, unsigned num_children, expr * const * children, expr_ref & result);
+    void pull_quant1(quantifier * q, expr * new_expr, expr_ref & result);
+    void pull_quant1(expr * n, expr_ref & result);
+    void pull_quant2(expr * n, expr_ref & r, proof_ref & pr);
+};
+
+/**
+   \brief After applying this transformation the formula will not
+   contain nested quantifiers.
+*/
+class pull_nested_quant : public simplifier {
+    pull_quant   m_pull;
+    virtual bool visit_quantifier(quantifier * q);
+    virtual void reduce1_quantifier(quantifier * q);
+public:
+    pull_nested_quant(ast_manager & m):simplifier(m), m_pull(m) { enable_ac_support(false); }
+    virtual ~pull_nested_quant() {}
+};
+
+#endif /* _PULL_QUANT_H_ */