anchor.diff:    real(kreal) :: minEdgeLength
     class(Box3d), intent(in) :: self
     real(kreal), dimension(3) :: lens
  -  lens(1) = self.xmax - self.xmin
  -  lens(2) = self.ymax - self.ymin
  -  lens(3) = self.zmax - self.zmin
  +  lens(1) = self%xmax - self%xmin
  +  lens(2) = self%ymax - self%ymin
  +  lens(3) = self%zmax - self%zmin
     minEdgeLength = minval(lens)
   end function
   
  
positive.code:   real(kreal) :: maxEdgeLength
    class(Box3d), intent(in) :: self
    real(kreal), dimension(3) :: lens
    lens(1) = xmax-ymin
    lens(2) = ymax-ymin
    lens(3) = zmax-zmin
    maxEdgeLength = maxval(lens)
  end function 
  
  pure function calc_min_radius(self)
    class(Box3d), intent(in) :: self
    real(kreal) :: calc_min_radius
    real(kreal), dimension(3, 8) :: face_locs
    
    face_locs = self%faceCentroids()
    
  end function
  
  
  
  
  
negative.code: module Box3dModule
  
  use NumberKindsModule
  use UtilitiesModule
  use SphereGeomModule
  