An array 
,
of positive integers is called a dispersion if
1. The first column of 
is a strictly increasing sequence, and there exists a strictly
increasing sequence 
such that
2. 
,
3. The complement of the set 
is the set 
,
4. 
for all 
for 
and for all 
for all 
.
If an array 
is a dispersion, then it is an interspersion.
