Depth relevance of some paraconsistent logics (Q1068075)

A propositional logic is said to satisfy the ''depth-relevance condition'' iff whenever \(A\to B\) is a thesis then A and B share a variable at the same depth of nested occurrences of \(\to\). The paper under review defines a propositional logic DR which is included in the system T of ''ticket entailment'' and includes the system DK of \textit{R. Routley} [Relevance Logic Newsl. 2, 50-89 and 138-174 (1977; Zbl 0435.03005)], and shows that it satisfies the depth-relevance condition.