anchor.diff:    integer,parameter::DIMS=3 !< dimensions
     integer,parameter::N_FACE=6 !< number of faces per cell
     
  +  ! public constants
  +  integer,parameter,public::OT_OUT=0
  +  integer,parameter,public::OT_IN=1
  +  integer,parameter,public::OT_CUT=2
  +  
     !> octree grid
     type,public::otGrid
       ! basic data
  
positive.code:     if(allocated(this%oid)) deallocate(this%oid)
      if(allocated(this%lvl)) deallocate(this%lvl)
      if(allocated(this%neib)) deallocate(this%neib)
    end subroutine
    
    !> position of cell k
  
negative.code:     allocate(this%oid(this%nC))
      allocate(this%lvl(this%nC))
      allocate(this%neib(N_FACE,this%nC))
      allocate(this%flag(this%nC))
      call ot_genConn(this%otree,this%oid,this%lvl,this%neib)
      this%flag(:)=OT_IN
    end subroutine
    
    !> clear this otGrid
  