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