{"id":"reformat-no-block-of-one","text":"The loop guard `len(digits) - i > 4` ensures the tail is never a single digit, so no output block has size 1.","truth_value":"IN","source":"entries/2026/06/06/reformat-phone-number-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"reformat-no-block-of-one","truth_value":"IN","reason":"premise"}]}}