(Data) Abstraction Nexus

Original Morris paper?
custodial
Persistant abstraction
in Scheme, too
in OCaml
Compound Abstraction
See ‘brands’ and ‘siblings’ here for clues to provide abstraction in Keykos. The brand is the mark by which siblings recognize each-other and establish a back-channel over which to communicate about unabstracted values.

Abstraction overlaps with synergy.