{"id":"btree-sibling-chain-maintained-across-mutations","text":"The B-tree sibling chain is actively maintained during all structural mutations with a fixed wire format: splits write the new right page with the old leaf's next_sibling pointer before rewriting the old leaf, deletions patch the previous sibling's pointer to splice out the removed leaf, and the next_sibling field sits at a fixed byte offset (bytes 3-6) enabling reliable traversal without full page deserialization.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["split-chain-rewiring-order","btree-leaf-sibling-patched-on-remove","btree-sibling-chain-fixed-offset"],"outlist":[],"label":"Split, delete, and read operations all respect and maintain the sibling chain through coordinated ordering and format invariants."}],"dependents":["btree-range-scan-provides-ordered-access"],"metadata":{"last_reviewed":"2026-05-30T09:01:17","review_result":"pass"},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"btree-sibling-chain-maintained-across-mutations","truth_value":"IN","reason":"SL justification valid","antecedents":["split-chain-rewiring-order","btree-leaf-sibling-patched-on-remove","btree-sibling-chain-fixed-offset"],"label":"Split, delete, and read operations all respect and maintain the sibling chain through coordinated ordering and format invariants."},{"node":"split-chain-rewiring-order","truth_value":"IN","reason":"premise"},{"node":"btree-leaf-sibling-patched-on-remove","truth_value":"IN","reason":"premise"},{"node":"btree-sibling-chain-fixed-offset","truth_value":"IN","reason":"premise"}]}}