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
This Is What You Came For among artists to 73). "This Is What You Came For" became Rihanna's 25th and Harris's fourth number one on the Hot Dance Club Songs Chart, where it became the first song since 2013's "Wake Me Up" to stay at number one for two weeks. As of October 2016, the single has sold 1.2 million copies in the United States. "This Is What You Came For" debuted at number one on the Scottish Singles Chart, and peaked at number one in Australia, Canada and Ireland. The song also reached the top 10 in Germany, Ireland, New Zealand, Switzerland, Belgium, Denmark, Finland,