Relations and geometric verification

Proposal is not proof

The deterministic solver proposes bounded candidates in dependency order. An independent evaluator measures the resulting geometry. Status can be satisfied, failed, unknown or unsupported. Timeout is not impossibility, and a successful placement is not automatically satisfaction. Hard feasibility and soft scoring are distinct.

Supported relation semantics

Relation	Evaluation and limits
on / supports	Ground/contact footprint on measured horizontal surface; holes matter. supports lowers inversely.
inside / contains	Containment only where supported cavity/occupancy evidence exists; contains is inverse inside.
beside	Target-local side, gap and along offset; rotated/scaled geometry is evaluated.
against	Contact/proximity relative to supported target geometry; no automatic arbitrary mesh fitting.
facing	Horizontal orientation toward target with optional yaw offset.
attached-to	Initial attachment offset; not a runtime mechanical joint.
keep-clear	Owner-local reserved volume and occupancy checks.
reachable-from	Explicit actor and manipulation/navigation/line-of-sight mode; each is a different predicate.

Temporal policy

Relations default to initial, hard and weight 1. Initial governs compilation. Monitor expresses observation where implemented; runtime observations do not rewrite source. Maintain is recognized syntax but is not an unrestricted constraint-maintenance engine: unsupported combinations are diagnosed. Static horizontal support and conservative bounded cavity checks are not general solid-geometry theorem proving.

Reach is not navigation planning

Compiler reachability uses explicit actor proxies, range and geometric tests. It does not promise a general route through stairs, moving doors or arbitrary meshes. Runtime preview has a separate bounded planar navigation system with continuous obstruction checks. A geometric unknown is never promoted to satisfied because an AI called an object “reachable”.