SHAWN MICHAEL STANDEFER2021-11-262021-11-262021-06-0117550203https://scholars.lib.ntu.edu.tw/handle/123456789/587912Anderson and Belnap presented indexed Fitch-style natural deduction systems for the relevant logics R, E, and T. This work was extended by Brady to cover a range of relevant logics. In this paper I present indexed tree natural deduction systems for the Anderson-Belnap-Brady systems and show how to translate proofs in one format into proofs in the other, which establishes the adequacy of the tree systems.relevant logics, natural deduction, translationsjournal article10.1017/S17550203190001332-s2.0-85103957616https://api.elsevier.com/content/abstract/scopus_id/85103957616