Infinity symbol symbol is encoded in Unicode at and in LaTeX as codice_1: formula_4. The Unicode set of symbols also includes several variant forms of the infinity symbol, that are less frequently available in fonts: , and in block Miscellaneous Mathematical Symbols-B. The acid-free paper symbol mentioned above is encoded separately as . 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
Hilbert symbol (for "n" prime) used the power residue symbol when "K" has residue characteristic coprime to "n", and was rather complicated when "K" has residue characteristic dividing "n". The Hilbert symbol is (multiplicatively) bilinear: skew symmetric: nondegenerate: It detects norms (hence the name norm residue symbol): It has the "symbol" properties: Hilbert's reciprocity law states that if "a" and "b" are in an algebraic number field containing the "n"th roots of unity then where the product is over the finite and infinite primes "p" of the number field, and where (,) is the Hilbert symbol of the completion at "p". Hilbert's