Questão jurídica principal
Whether the pension fund had standing to appeal the cantonal judgment under Art. 89 BGG.
Decisão extraída
The fund lacked formal standing because it did not take part in the cantonal proceedings after being invited to submit observations.
Fundamentação extraída
A BVG insurer may generally appeal IV decisions affecting its obligations, but here the procedural prerequisite of participation under Art. 89(1)(a) BGG was not met; the invitation to comment and failure to do so meant no admissible appeal interest for this case.