The shape of Latin S arises from Greek Σ by dropping just one out of the four strokes of that letter. The (angular) S-condition made up of a few strokes existed to be a variant of your 4-stroke letter Σ now in the epigraphy of Western Greek alphabets, as well https://s54207.humor-blog.com/30529713/facts-about-bud-naked-mushrooms-revealed