{"id":"pigeonhole-26-letter-bound","text":"The first-letter-to-appear-twice loop executes at most 27 iterations regardless of string length, since 26 lowercase letters force a collision by the 27th character via the pigeonhole principle.","truth_value":"IN","source":"entries/2026/06/06/first-letter-to-appear-twice-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"pigeonhole-26-letter-bound","truth_value":"IN","reason":"premise"}]}}