  This section describes Sylvan’s work as part of the Canberra Logic Group’s pioneering research on relevant and paraconsistent logics, and applications to naïve set theory. In the mid-1970s, Routley/Sylvan produced a closely interconnected body of work (1975; Routley and Meyer 1976, 1977, 1979; Routley et al. 1982), much of it in collaboration with Val Plumwood (then Routley), Meyer, Brady, and Priest (e.g., Priest and Routley 1983), circling around a few key ideas, the germs of which we have already met: universality; implication and entailment; and inconsistency. We now visit these in turn.