Sticky Values as a partial antidote to the conservatism of memos
Idea: Whenever we skip over a variable V during DDB, we record the current value u of V.
When we come back down to V (aftrer having re-assigned its ancestors), we first try
Leads up-to 4x further speedup over and above EBL/DDB
Problem: Memoization ignores no-goods of the type