Abstract

[10] offers two (cut-free) subscripted Gentzen systems, G 2 T + and G 2 R +, which are claimed to be equivalent in an appropriate sense to the positive relevant logics T + and R +, respectively. In this paper we show that that claim is false. We also show that the argument in [10] for the further claim that cut and/or modus ponens is admissible in two other subscripted Gentzen systems, G 1 T + and G 1 R +, is unsound.