{"id":"negation-marking-abs-required","text":"In the negation-marking pattern, `abs()` is required when reading a cell's value (as opposed to its sign) because earlier iterations may have negated it; omitting `abs()` would produce negative indices and raise `IndexError`.","truth_value":"IN","source":"entries/2026/06/06/find-all-numbers-disappeared-in-an-array-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"negation-marking-abs-required","truth_value":"IN","reason":"premise"}]}}