{"id":"subtree-sum-return-contract","text":"`subtree_sum` always returns the sum of all node values in its subtree, never the tilt; tilt is accumulated separately via the `nonlocal total_tilt` side effect.","truth_value":"IN","source":"entries/2026/06/06/binary-tree-tilt-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"subtree-sum-return-contract","truth_value":"IN","reason":"premise"}]}}