anchor.diff:      end do
     end subroutine
     
  +  !> cell left node
  +  elemental function ClN(n)
  +    integer,intent(in)::n !< cell index
  +    integer ClN !< result
  +    
  +    ClN=n
  +  end function
  +  
  +  !> cell right node
  +  elemental function CrN(n)
  +    integer,intent(in)::n !< cell index
  +    integer CrN !< result
  +    
  +    CrN=n+1
  +  end function
  +  
  +  !> cell left cell
  +  elemental function ClC(n)
  +    integer,intent(in)::n !< cell index
  +    integer ClC !< result
  +    
  +    ClC=n-1
  +  end function
  +  
  +  !> cell right cell
  +  elemental function CrC(n)
  +    integer,intent(in)::n !< cell index
  +    integer CrC !< result
  +    
  +    CrC=n+1
  +  end function
  +  
  +  !> node left cell
  +  elemental function NlC(n)
  +    integer,intent(in)::n !< node index
  +    integer NlC !< result
  +    
  +    NlC=n-1
  +  end function
  +  
  +  !> node right cell
  +  elemental function NrC(n)
  +    integer,intent(in)::n !< node index
  +    integer NrC !< result
  +    
  +    NrC=n
  +  end function
  +  
  +  !> node left node
  +  elemental function NlN(n)
  +    integer,intent(in)::n !< node index
  +    integer NlN !< result
  +    
  +    NlN=n-1
  +  end function
  +  
  +  !> node right node
  +  elemental function NrN(n)
  +    integer,intent(in)::n !< node index
  +    integer NrN !< result
  +    
  +    NrN=n+1
  +  end function
  +  
   end module
  
positive.code:   end subroutine
    
    !> generate uniform grid
    elemental subroutine genUniformGrid1D(this,boundL,boundR,nCell)
      class(typeGrid1D),intent(inout)::this !< this grid
      double precision,intent(in)::boundL !< left bound
      double precision,intent(in)::boundR !< right bound
  
negative.code: !> 1-dimensional grid
  module moduleGrid1D
    private
    
    ! constants
    integer,parameter,public::BIND_NODE=1 !< bind with node
    integer,parameter,public::BIND_CELL=2 !< bind with cell
    
    !> 1-dimensional grid data and procedures
    type,public::typeGrid1D
  