INTERN (4.4.6 vs. 5.0.2)
CL-USER 1 > (lisp-implementation-type) "LispWorks" CL-USER 2 > (lisp-implementation-version) "4.4.6" CL-USER 3 > (intern nil) Error: In a call to INTERN: NIL is not of type STRING. 1 (abort) Return to level 0. 2 Return to top-level loop. 3 Return from multiprocessing. CL-USER 1 > (lisp-implementation-type) "LispWorks" CL-USER 2 > (lisp-implementation-version) "5.0.2" CL-USER 3 > (intern nil) NIL :INHERITED The first example is on Linux, the second one on Windows, if that matters. I think the new behaviour of LW 5 is wrong - the Hyperspec says that the first argument to INTERN must be a string, not a string designator. Cheers, Edi.