{"id":"check-double-zero-pair","text":"Two zeros in the input correctly return `True` because the second zero finds `2 * 0 = 0` already in `seen` from the first zero","truth_value":"IN","source":"entries/2026/06/06/check-if-n-and-its-double-exist-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"check-double-zero-pair","truth_value":"IN","reason":"premise"}]}}