Substructural Logics in Natural Deduction

Abstract

Extensions of Natural Deduction to Substructural Logics of Intuitionistic Logic are shown: Fragments of Intuitionistic Linear, Relevant and BCK Logic. Rules for implication, conjunction, disjunction and falsum are defined, where conjunction and disjunction respect contexts of assumptions. So, conjunction and disjunction are additive in the terminology of linear logic. Explicit contraction and weakening rules are given. It is shown that conversions and permutations can be adapted to all these rules, and that weak normalisation and subformula property holds. The results generalise to quantification.