... suggests another view of the subject with focusing on the cardinality of monochro-matic symmetric subsets irrespective of the measure-theoretic aspects. § 7 contains a list of open problems.Techniques ... B ⊆ A of measureµ(B) ≥ µ(A)2.(SL) Every measurable set A ⊂ Ωofmeasure0<µ(A) < 1 contains a symmetricsubset B ⊆ A of measure µ(B) >µ(A)2.(U) ms(Ω,r) ≤ 1/r2.The proof of (L) ... colors of {a, b, c} and colors of {−a, −b, −c} do not intersect and, hence, {h(a),h(b),h(c)} and {h(−a),h(−b),h(−c)}are disjoint sets of vertices of the triangle T . Therefore, convex hulls of these...