{"id":"ugly-number-trial-division-pattern","text":"`is_ugly` uses the strip-and-check-residual pattern: divide out all factors of 2, 3, and 5, then check if the remainder is 1","truth_value":"IN","source":"entries/2026/06/06/ugly-number-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"ugly-number-trial-division-pattern","truth_value":"IN","reason":"premise"}]}}