Graham says Arc had to be frozen because other programs depended on it. Indeed, much of Lisp language design came about by demands of the applications that use

Graham says Arc had to be frozen because other programs depended on it. Indeed, much of Lisp language design came about by demands of the applications that used it. So, is Bel finished or still changing? Are there other programs that depend on it? If Bel is developed "axiomatically", maybe not programs, but more thinking about the theory of computation may be its driver of change.