{"id":"btree-height-never-shrinks","text":"Since delete never merges internal nodes or demotes the root, tree height only increases (on splits) and never decreases, regardless of how many keys are deleted.","truth_value":"IN","source":"entries/2026/05/28/topic-b-tree-underflow-rebalancing.md","source_url":"","source_hash":"","justifications":[],"dependents":["btree-delete-causes-monotonic-degradation"],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"btree-height-never-shrinks","truth_value":"IN","reason":"premise"}]}}