A one-dimensional commutative formal group law over a commutative ring 
is a formal
power series ![F(X,Y) in R[[X,Y]]](/images/equations/FormalGroup/Inline2.svg)
satisfying identity, associativity, and commutativity: 
, 
, and 
. It is the infinitesimal power-series analogue
of an algebraic group.
Formal Group
See also
Algebraic Group, Formal Power Series, RingExplore with Wolfram|Alpha
References
Hazewinkel, M. Formal Groups and Applications. New York: Academic Press, 1978.Cite this as:
Weisstein, Eric W. "Formal Group." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/FormalGroup.html