Not bad! Except you used "said": > a plurality of non-intersecting surfaces arranged in layers, each surface comprising multiple units, combinations of said un

Not bad! Except you used "said": > a plurality of non-intersecting surfaces arranged in layers, each surface comprising multiple units, combinations of said units forming passing and blocking tuples, each tuple comprising one unit from each of said surfaces such that the projected path of any specific particle through the filter traverses a single tuple In fairness, I'm not sure "the" was generally accepted in 1991.