Why intuitionistic relevant logic cannot be a core logic

Abstract

At the end of the 1980s, Tennant invented a logical system that he called "intuitionistic relevant logic" (IR, for short). Now he calls this same system "Core logic." In Section 1, by reference to the rules of natural deduction for IR, I explain why IR is a relevant logic in a subtle way. Sections 2, 3, and 4 give three reasons to assert that IR cannot be a core logic.