Small But Robust Bug in Gabriel and Steele's "Evolution of Lisp."

Although not nearly as intriguing as  the bugs in early definitions of EVAL , this bug is still interesting example of vitality and robustness: it is typical specimen, found on quite visible place, yet it passed unnoticed by two authors and few reviewers.

(Unrelated: if you'd like to see the solution of the third problem, it is not in  Evolution of Lisp ; instead, you're directed to MIT AI "memos"  AIM-452  and  AIM-453 .)