함수형 프로그래밍
A variation is found on page 269 in the index of some editions of Brian Kernighan and Dennis Ritchie's book "The C Programming Language"; the index entry recursively references itself ("recursion 86, 139, 141, 182, 202, 269"). Early versions of this joke can be found in "Let's talk Lisp" by Laurent Siklóssy (published by Prentice Hall PTR on December 1, 1975 with a copyright date of 1976) and in "Software Tools" by Kernighan and Plauger (published by Addison-Wesley Professional on January 11, 1976). The joke also appears in "The UNIX Programming Environment" by Kernighan and Pike. It did not appear in the first edition of "The C Programming Language". The joke is part of the Functional programming folklore and was already widespread in the functional programming community before the publication of the aforementioned books.