This is the lambda-lists package by Alan Jeffrey, for doing lists and lambda calculus via expandable macros (a.k.a. in TeX's mouth). For historical reasons, the code is available in a file named lambda.sty; it runs under both plain TeX and LaTeX. It is unrelated to the lambda format that is part of Omega. The documentation is in lambda-lists.{tex,pdf}. It was originally published as an article in TUGboat, vol.11, no.2, pp.237-245. http://tug.org/TUGboat. The entire package is released under the LPPL. It consists of this README, lambda.sty, lambda-lists.tex, and the derived file lambda-lists.pdf. Web page with contact info: http://ect.bell-labs.com/who/ajeffrey.