Published online by Cambridge University Press: 12 March 2014
Some of the theorems contained in the interesting and incisive paper [*] (D. J. Shoesmith and T. J. Smiley, Deducibility and many-valuedness, this Journal, vol. 36 (1970), pp. 610–622) are strongly connected with some earlier results, especially those presented in the paper of Łoś and Suszko [2]. The lack of appropriate bibliographical references in [*] shows that some results which have been obtained relatively long ago are, unfortunately, not so widely known as one might expect. The main task of this short note is to inform briefly on a few results and problems related to those examined in [*].