lazylist – Lists in TeX’s “mouth”

The pack­age was de­vel­oped to pro­vide flex­i­ble lists, whose or­der­ing can be al­tered on the fly.
The im­ple­men­ta­tion in­volves a pile of lambda-cal­cu­lus and list-han­dling macros of an in­cred­i­bly ob­tuse na­ture. The TUGboat pa­per serves as a man­ual for the macros.
Hav­ing said all of which, con­fi­dence is en­hanced by the knowl­edge that the TeX code was for­mally ver­i­fied.