{"id":"most-frequent-even-negative-one-sentinel","text":"`most_frequent_even` returns `-1` (not `None` or an exception) when the input contains no even numbers — this is the sentinel convention for this problem.","truth_value":"IN","source":"entries/2026/06/06/most-frequent-even-element-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"most-frequent-even-negative-one-sentinel","truth_value":"IN","reason":"premise"}]}}