From gutenberg_org@mastodon.social on Mastodon: English Mathematician John Wallis died # OTD in 1703. In 1657 Wallis published the Mathesis Universalis (“Universal Mathematics”), on algebra, arithmetic, and geometry, in which he further developed notation. He invented and introduced the symbol ∞ for infinity. He similarly used 1/∞ for an infinitesimal. John Wallis…