The shape of Latin S arises from Greek Σ by dropping just one out of the 4 strokes of that letter. The (angular) S-condition made up of a few strokes existed to be a variant on the 4-stroke letter Σ by now in the epigraphy of Western Greek alphabets, as https://donovanxyjdx.aioblogs.com/84712132/rumored-buzz-on-bud-naked