Nu as a concrete shape of the interaction model. The premise, the structural distinction, the two main dimensions, and the atom kinds that fall out.
- 00-foundations.md - what Nu is: Ref | Interaction, composition, Context update as the dimension.
- 01-atom.md - atom vs composition: the foundational distinction. Every later rule lives at one of these two levels.
- 02-mutation.md - first dimension: mutation and the observability invariant that falls out.
- 03-cardinality.md - second dimension: scalar, stream, void.
- 04-kinds.md - Ref, Query, Command, Action, Flow, Span. The kinds that fall out of crossing the two dimensions.