{"id":"quadtree-boundary-first-child-wins","text":"Quadtree `_contains` uses inclusive bounds (`<=`), so a point on the boundary of multiple children is inserted into the first matching child in NW → NE → SW → SE order","truth_value":"IN","source":"entries/2026/06/05/proximity-service-proximity_service.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"quadtree-boundary-first-child-wins","truth_value":"IN","reason":"premise"}]}}