Corollary 5.
Assuming that:
A
⊂
[
n
]
(
r
)
with
|
x
∩
y
|
⁄
≡
r
(
m
o
d
p
)
, for each distinct
x
,
y
∈
A
, where
p
<
r
is prime
Then
|
A
|
≤
n
p
−
1
.