Kernrechtsfrage
Whether the federal appeal was admissible.
Extrahierter Entscheid
The appeal in public law matters was admissible because it challenged a final cantonal decision in a public-law matter and the federal office was entitled to appeal.
Extrahierte Begründung
The case fell under Art. 82 lit. a and Art. 86 Abs. 1 lit. d BGG, with no exclusion ground; the migration authority had standing under Art. 89 Abs. 2 lit. a BGG.