#ifndef SPACEDIFF_HEADER
#define SPACEDIFF_HEADER 1
/////////////////////////////////////////////////////
//! rcsid="$Id: SpaceDiff.hh,v 1.8 2000/08/17 15:18:09 ees1cg Exp $"
//! file="amma/Logic/Learn/SpaceDiff.hh"
//! lib=VLLearn
//! author="Charles Galambos"
//! date="26/10/98"
//! docentry="Logic.Learn"

#include "amma/Logic2/SpaceSet.hh"
#include "amma/DList.hh"

////////////////////////////////////////////////////
//: Find the difference between a set of spaces and a new space.
//! userlevel=Develop.
// This class attempts to find a difference which will distinguish
//  between VLSpaceSetC and VLSpaceC, this is returned.

class VLSpaceDiffBodyC
  : public BodyRefCounterVC
{
public:
  VLSpaceDiffBodyC();
  //: Default constructor.
  
  virtual DListC<VLSymbC> Apply(const VLSpaceSetC &set,const VLSpaceC &it);
  //: Find the difference between a set of spaces and another space.
  
  static VLSpaceSetC PosDecrimSet(VLSpaceSetC &exStates,const VLMinTermC &diff);
  //: Add all states 'diff' decriminates positively (is true in)  to Result, 
  //: count the number added.
  
protected:
  BooleanT CheckDescrim(const VLSpaceSetC &set,const VLSpaceC &it,const VLSymbC &diff);
  //: Check the ability of diff to descriminate between 'set' and it.
  
};

//////////////////////////////////////////////////////
//: Find the difference between a set of spaces and a new space.
//! userlevel=Normal
// This class attempts to find a difference which will distinguish
//  between VLSpaceSetC and VLSpaceC, this is returned.

class VLSpaceDiffC 
  : public RCHandleC<VLSpaceDiffBodyC>
{
public:
  VLSpaceDiffC()
    {}
  //: Default constructor.

  VLSpaceDiffC(BooleanT x)
    : RCHandleC<VLSpaceDiffBodyC>(*new VLSpaceDiffBodyC ())
    {}
  //: Constructor.
  
protected:
  VLSpaceDiffC(VLSpaceDiffBodyC &body)
    : RCHandleC<VLSpaceDiffBodyC>(body)
    {}
  //: Body constructor.
  
  VLSpaceDiffBodyC &Body()
    { return RCHandleC<VLSpaceDiffBodyC>::Body(); }
  //: Access body.
  
  const VLSpaceDiffBodyC &Body() const
    { return RCHandleC<VLSpaceDiffBodyC>::Body(); }
  //: Access body.
  
public:
  
  DListC<VLSymbC> Apply(const VLSpaceSetC &set,const VLSpaceC &it)
    { return Body().Apply(set,it); }
  //: Find the difference between a set of spaces and another space.
  
};



#endif