ISO 31-11:1992 was the part of international standard ISO 31 that defines mathematical signs and symbols for use in physical sciences and technology. It was superseded in 2009 by ISO 80000-2:2009 and subsequently revised in 2019 as ISO-80000-2:2019. It included definitions for symbols for mathematical logic, set theory, arithmetic and complex numbers, functions and special functions and values, matrices, vectors, and tensors, coordinate systems, and miscellaneous mathematical relations.
See also Mathematical symbols Mathematical notation
References and notes