Structure code so that the set of representable states equals the set of valid states for a given domain, resolving the boundary condition d(S) → ∅. Each domain is a type boundary; closing it adds a constraint layer. Domains have prerequisites — valid(Dn) requires closed(Dm) for all prerequisites Dm
Structure code so that the set of representable states equals the set of valid states for a given domain, resolving the boundary condition d(S) → ∅. Each domain is a type boundary; closing it adds a constraint layer. Domains have prerequisites — valid(Dn) requires closed(Dm) for all prerequisites Dm. Use when designing types, schemas, state machines, or any structure where invalid states should be