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 or other quantities, 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.

Index of articles associated with the same name

This article includes a list of related items that share the same name (or similar names).
If an internal link incorrectly led you here, you may wish to change the link to point directly to the intended article.