Infinity symbol Infinity symbol The infinity symbol (sometimes called the lemniscate) is a mathematical symbol representing the concept of infinity. The shape of a sideways figure eight has a long pedigree; for instance, it appears in the cross of Saint Boniface, wrapped around the bars of a Latin cross. However, John Wallis is credited with introducing the infinity symbol with its mathematical meaning in 1655, in his "De sectionibus conicis". Wallis did not explain his choice of this symbol, but it has been conjectured to be a variant form of a Roman numeral for 1,000 (originally CIƆ, also CƆ), which was sometimes
Natural number as the symbol for this set. To be unambiguous about whether 0 is included or not, sometimes a subscript (or superscript) "0" is added in the former case, and a superscript "" or subscript "" is added in the latter case: Alternatively, since natural numbers naturally embed in the integers, they may be referred to as the positive, or the non-negative integers, respectively. The set of natural numbers is an infinite set. This kind of infinity is, by definition, called countable infinity. All sets that can be put into a bijective relation to the natural numbers are said to have