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 symbol notation for summations and limits such as the infinity sign is conventionally interpreted as meaning that the variable grows arbitrarily large (towards infinity) rather than actually taking an infinite value. The infinity symbol may also be used to represent a point at infinity, especially when there is only one such point under consideration. This usage includes, for instance, the infinite point of a projective line, and the point added to a topological space formula_2 to form its one-point compactification formula_3. In areas other than mathematics, the infinity symbol may take on other related meanings; for instance, it has been used