mechanism now quickly because i know you all know what it is but very quickly you want to perform this action right here over a region right here so there is always a query and now the subscripts here are going to be important in this paper okay so the query is at a given position position o and you can see that's the o right here that's the i'm going to call it the output i guess that's what they said as well so the output position you want to go over all of the input positions and you want to aggregate data from all