MathDB

In an

n

-element set

S

, several subsets

A_1, A_2, \ldots , A_k

are distinguished, each consists of at least two, but not all elements of

S

. What is the largest

k

that it’s possible to write down the elements of

S

in a row in the order such that we don’t find all of the element of an

A_i

set in the consecutive elements of the row?

Problem Statement