We could say that that's the same thing as the sub matrix, if we called this guy-- let me write it this way-- if we got rid of this guy's row and this guy's column, if we had just our traditional matrix where this wasn't replaced. If we just had an ai1 here, ai2, its sub matrix would be the same thing, because we're crossing out this row and this column. So it would be all of these guys and all of these guys down here.