Scope and guarantees

Sectile covers deterministic interaction over finite, resource-bounded domains with stable identity, immutable snapshots, explicit semantic input, and ordered host commands.

Guaranteed

• Stable identity and deterministic observations.
• Typed construction and transition failures.
• Controlled and uncontrolled state ownership.
• Failure-atomic transitions and stale revision rejection.
• Exact quantized ranges and bounded navigation.
• Ordered hierarchy, logical coordinates, selection, expansion, and plain-text editing.
• Host-independent semantics with DOM, terminal, and framework projection.

Explicit host responsibilities

• Pixel geometry, collision detection, layout, and animation.
• Native focus execution, pointer capture, scrolling, and accessibility projection.
• Terminal cursor placement, input decoding, and display-width rendering.
• Framework lifecycle, component composition, and styling.
• Application persistence, network requests, and product-specific validation.

Separate models

The current theory does not reinterpret the following domains as sequence, range, grid, or tree:

• General graph or DAG traversal.
• Unbounded streams and backpressure.
• Rich documents, rich-text marks, and collaborative editing.
• Spatial geometry and visual-nearest navigation.
• Overlapping or merged grid regions.

These domains require their own observations, laws, failures, and cost contracts.