Two closely related laws of number operations.
In symbols, they are stated: a + (b + c) = (a + b) + c , and a (bc) = (ab) c . Stated in words: The terms or factors may be associated in any way desired and the result will be the same. This holds for the numbers generally encountered: positive and negative, integral and fractional, rational and irrational, real and imaginary. Exceptions occur (e.g., in nonassociative algebras and divergent infinite series ). See also commutative law , distributive law .