# Formal sum

In mathematics, a **formal sum**, **formal series**, or **formal linear combination** may be:

- In group theory, an element of a free abelian group, a sum of finitely many elements from a given basis set multiplied by integer coefficients.
- In linear algebra, an element of a vector space, a sum of finitely many elements from a given basis set multiplied by real, complex, or other numerical coefficients.
- In the study of series (mathematics), a sum of an infinite sequence of numbers, considered as an abstract mathematical object regardless of whether the sum converges.
- In the study of power series, a sum of infinitely many monomials with distinct positive integer exponents, again considered as an abstract object regardless of convergence.

This article is issued from
Wikipedia.
The text is licensed under Creative
Commons - Attribution - Sharealike.
Additional terms may apply for the media files.