Nuel Belnap

Nuel Belnap (born 1930) is an American philosopher and logician, emeritus professor at the University of Pittsburgh, who co-founded the field of relevance logic with his mentor Alan Ross Anderson and continued to develop it after Anderson's death in 1973. Belnap's most influential technical contribution is the Routley-Meyer semantics (with Richard Routley and Robert K. Meyer), which provided the first rigorous model theory for relevance logics using a ternary accessibility relation. Beyond relevance logic, Belnap has made foundational contributions to the logic of questions, the theory of truth (notably the truth-value gap framework), and the formal analysis of agency and choice in branching time.\n\n\n\n