A
lattice is an abstract structure studied in the
mathematical subdisciplines of
order theory and
abstract algebra. It consists of a
partially ordered set in which every two elements have a unique
supremum (also called a least upper bound or
join) and a unique
infimum (also called a greatest lower bound or
meet). An example is given by the
natural numbers, partially ordered by
divisibility, for which the unique supremum is the
least common multiple and the unique infimum is the
greatest common divisor.