Questione giuridica chiave
Whether the public-law appeal against the tax judgment was sufficiently reasoned under Art. 42 BGG.
Decisione estratta
The appeal did not engage with the decisive reasoning of the cantonal judgment and therefore lacked a sufficient substantiated challenge.
Motivazione estratta
A mere reference to earlier correspondence and general assertions about double taxation or tax fairness is not enough; the appellants had to address the detailed findings on individual asset inflows and expenses.