We will go on an adventure to automate the merkleization of arbitrary data structures, along which we will visit concepts including recursion schemes, generalized polynomials, derivatives of data structures, zippers, lenses, reference functors, content-addressing, metaprogramming, incremental and modular programming (aka OO), and category theory.

_Orthogonal Persistence_: You bind variable `x` to 42 at your REPL, but thensome “youths” steal your laptop while orcs raze your datacenter to the ground.So you move to a safer place, get a new laptop, and enter your passphrase in it;the system downloads encrypted backups from redundant datacenters on multipleother continents; after a few minutes, your interface is restored to thesame state it was when you left it, and variable `x` is still bound to 42.Yet not one single instructions in any of your applications ever hadto even mention anything about storage and retrieval.I will present an original re-framing of Orthogonal Persistence,as refactored into a simple set of concepts. Surprisingly perhaps, I will explain why transactions provide an inherently bad non-modular API, while their opposite, "anti-transactions" (critical sections) are good and modular.