The Hausdorff outer measure is different from the unbounded Hausdorf content in that rather than considering all possible coverings of S, we see what happens when the sizes of the balls go to zero. This is for <math>d \geq 0 </math>, we define the d-dimensional Hausdorff outer measure of S as | The Hausdorff outer measure is different from the unbounded Hausdorf content in that rather than considering all possible coverings of S, we see what happens when the sizes of the balls go to zero. This is for <math>d \geq 0 </math>, we define the d-dimensional Hausdorff outer measure of S as |