Title:   ACL2 Function Memoization and Fast Association Lists
Authors:                     Boyer and Hunt

We present an update of our implementation work on fast association lists
and function memoization.  We give a review of Hash CONS, and the ACL2
function definitions and theorems that define our system.
We present several examples of the usage of this system, and we discuss
reasoning about the uniqueness of ACL2 data objects.