Before revision: He was answered by Nuel Belnap, that even though introduction and elimination rules can constitute meaning, not just any pair of such rules will determine a meaningful expression – they must meet certain constraints, such as not allowing us to deduce any new truths in the old vocabulary.
After revision: He was answered by Nuel Belnap, that even though introduction and elimination rules can constitute meaning, not just any pair of such rules will determine a meaningful expression — they must meet certain constraints, such as not allowing us to deduce any new truths in the old vocabulary.