Infinity symbol in bookbinding to indicate that a book is printed on acid-free paper and will therefore be long-lasting. In modern mysticism, the infinity symbol has become identified with a variation of the ouroboros, an ancient image of a snake eating its own tail that has also come to symbolize the infinite, and the ouroboros is sometimes drawn in figure-eight form to reflect this identification, rather than in its more traditional circular form. In the works of Vladimir Nabokov, including "The Gift" and "Pale Fire", the figure-eight shape is used symbolically to refer to the Möbius strip and the infinite, for instance
Infinity calculations by dividing the region into infinitesimal strips of width on the order of formula_2 But in "Arithmetica infinitorum" (1655 also) he indicates infinite series, infinite products and infinite continued fractions by writing down a few terms or factors and then appending "&c." For example, "1, 6, 12, 18, 24, &c." In 1699 Isaac Newton wrote about equations with an infinite number of terms in his work "De analysi per aequationes numero terminorum infinitas". Hermann Weyl opened a mathematico-philosophic address given in 1930 with: The infinity symbol formula_1 (sometimes called the lemniscate) is a mathematical symbol representing the concept of