009 Learning Sushi Science without actual research

My microphone apparently was not turned on, so this is a silent film. But be sure to pause when I highlight a combinator to get an idea. All design credit goes to Kitch and this video: • Factorio 0.17 | Back T...
I was testing out building a sushi belt of science but without having to deal with research labs. The idea is that the constant combinator is sending out a signal on the red wire of "S" with a value of 20. The first arithmetic combinator acts as a counter to count (on green wire circuit) each item that enters the segment of the belt. It sends out a signal for each item (each science pack) and the value counted.
On the belt itself, the condition is that if that item is less than "S", run the belt, otherwise stop. This means only "S" (20) items can pass the belt. Then on a different circuit, each inserter is wired up and passes a signal of 1 back to a second combinator. That combinator multiples the value by -1 and passes it to the first combinator. If that first combinator has counted red science to 20 and the second combinator send red science -1, the first combinator sends "red science 19" and the belt moves another item forward, sending "red science +1" and moving "red science" back to 20, stopping the belt.