{"id":"mountain-peak-must-be-interior","text":"The valid-mountain-array solution requires the peak index to satisfy `0 < peak < n-1`, rejecting purely monotonic sequences even when both pointers converge.","truth_value":"IN","source":"entries/2026/06/06/valid-mountain-array-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"mountain-peak-must-be-interior","truth_value":"IN","reason":"premise"}]}}