Formal power series
GENERALIZATION OF A POLYNOMIAL, WHERE THE NUMBER OF TERMS IS ALLOWED TO BE INFINITE, DEFINED ALGEBRAICALLY WITHOUT CONSIDERATION OF CONVERGENCE (SO THAT E.G. EVALUATION IS NOT ALWAYS DEFINED)
Formal Laurent series; Formal series; Non-commuting formal power series; Power series ring; Ring of formal power series; K((x)); R((x)); Ring of formal Laurent series; Formal power series ring; Magnus ring; Formal power serie; Formal power series over a semiring; Operations on formal power series
In mathematics, a formal series is an infinite sum that is considered independently from any notion of convergence, and can be manipulated with the usual algebraic operations on series (addition, subtraction, multiplication, division, partial sums, etc.).