text: /*++
  Copyright (c) 2006 Microsoft Corporation
  
  Module Name:
  
      occurs.h
  
  Abstract:
  
      <abstract>
  
  Author:
  
      Leonardo de Moura (leonardo) 2007-06-07.
  
  Revision History:
  
  --*/
  #pragma once
  
  class expr; 
  class func_decl;
  
  /**
     \brief Return true if n1 occurs in n2
  */
  bool occurs(expr * n1, expr * n2);
  
  /**
     \brief Return true if d is used in n
  */
  bool occurs(func_decl * d, expr * n);
  
  
  