Questione giuridica chiave
Whether Y.________ had standing to file the federal appeal
Decisione estratta
Y.________ lacked standing because he had not participated before the cantonal court and did not claim to have been prevented from doing so.
Motivazione estratta
Only a person who participated in the prior instance, or was denied the possibility to do so, may appeal under Article 89(1)(a) LTF.