Let 
 denote anything subject to weighting by a normalized linear scheme of weights that
 sum to unity in a set 
. The Kolmogorov axioms state that 
1. For every 
 in 
,
 there is a real number 
 (the Kolmogorov weight of 
) such that
2. ,
 where 
 denotes the complement of 
 in 
. 
3. For the mutually exclusive subsets , 
, ... in 
,