Abstract: | Let Mn=X1+ +Xn be a martingale with differences Xk=Mk–Mk–1bounded from above such that with some non-random positive k.Let the conditional variance 2k=E(X2k|X1,...,Xk–1) satisfy 2ks2k with probability one, where s2k are some non-random numbers. Write 2k=max{2k,s2k} and 2=21+ +2n. We prove the inequalitywith a constant . |