A Coxeter matrix is an 
square matrix 
with
 |  |  |
(1)
|
 |  |  |
(2)
|
where the first condition holds for 
, ..., 
, and the second for distinct 
. The value 
indicates that no relation is imposed on that pair of
generators.
Coxeter Matrix
See also
Artin Group, Artin Parabolic Subgroup, Coxeter GroupExplore with Wolfram|Alpha
References
Buekenhout, F. and Parker, M. "The Number of Nets of the Regular Convex Polytopes in Dimension
." Disc. Math. 186, 69-94, 1998.Referenced on Wolfram|Alpha
Coxeter MatrixCite this as:
Weisstein, Eric W. "Coxeter Matrix." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/CoxeterMatrix.html