RFC 0001 — Multi-level document model

Document status: proposed. Canonical source.

Decision

Adopt a containment tree with stable identity plus coordinated relationship graphs and explicit authored→resolved evaluation layers.

Why

A single shape tree conflates semantics, layout, rendering and relationships. MLIR demonstrates multiple abstraction levels; OpenUSD demonstrates graph-like composition over a scene namespace.

Rejected

• pure AST: too source-language-specific;
• pure scene graph: loses authored semantics;
• pure ECS: efficient implementation technique but weak interchange semantics;
• event log as canonical state: burdens simple offline documents;
• relational tables as interchange syntax: poor human authoring and containment ergonomics.