A reduced root system is a root system 
satisfying the additional property that, if 
, then the only multiples of 
in 
are 
.
Reduced Root System
See also
Lie Algebra, Root SystemExplore with Wolfram|Alpha
References
Andrews, G. E. q-Series: Their Development and Application in Analysis, Number Theory, Combinatorics, Physics, and Computer Algebra. Providence, RI: Amer. Math. Soc., p. 40, 1986.Humphreys, J. E. Introduction to Lie Algebras and Representation Theory, 3rd ed. New York: Springer-Verlag, 1977.Referenced on Wolfram|Alpha
Reduced Root SystemCite this as:
Weisstein, Eric W. "Reduced Root System." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ReducedRootSystem.html