Abstract. If B is an uncountable set then there is a function r:ixi-»Rt for which there is no function t: B -» R + such that r(6" b2) < f(6,) ■ t(b2) for all bx, b2 e B. Here N denotes the set of all positive integers. Note that the theorem fails if B is countable. Let R+ be the set of all nonnegative reals.
Corollary.If B is an uncountable set then there is a function r: B X B -> R+ for which there is no function t: B -* R+ such that r(bx, b2) < t(b) ■ t(b2) for all ¿>" b2 £ B.Proof. Replace the function r by its square r2. □ This corollary answers a question of Leopoldo Nachbin. In [1], the corollary is proved for sets B whose size is at least the continuum and is used (in Lemma 19) to give an example of a discontinuous 2-homogeneous complex polynomial on a locally convex complex vector space (with basis B).Proof of theorem. It suffices to prove the theorem for a set B of cardinality N,. Thus let us assume that B is the set of all countable ordinal numbers. Let < be the well ordering of ordinal numbers.If a £ B, let Wa be the set of all ordinal numbers that are smaller than a; each Wa is at most countable. For each a £ B, let ra be some one-to-one mapping of Wa into N. If a, b £ B, we define r(a, b) = ra(b) whenever a > b, and arbitrarily otherwise.I shall show that the function r: B X B -» N satisfies the statement of the theorem. Thus let / be an arbitrary function from B into N. We want to find a,b £ B such that r(a, b) > t(a) and r(a, b) > t(b).Since B is uncountable,2 there is an uncountable subset C of B such that t is constant on C, with value «. Let a £ C be, such that a has infinitely many