Theorem 4
(Frankl-Wilson Theorem)
.
Assuming that:
p
is prime
λ
1
,
…
,
λ
s
(
s
≤
r
)
λ
i
⁄
≡
r
(
m
o
d
p
)
for each
i
A
⊂
X
(
r
)
such that for all distinct
x
,
y
∈
A
have
|
x
∩
y
|
≡
λ
i
(
m
o
d
p
)
for some
i
Then
|
A
|
≤
n
s
.