Questão jurídica principal
Whether the complaint against the cantonal court's joinder decision was admissible under Art. 87 OG
Decisão extraída
The joinder decision was a final decision for the appellant and had to be challenged immediately; the later constitutional complaint was therefore inadmissible.
Fundamentação extraída
The court held that the decision definitively determined the appellant's procedural position, and because later participation could no longer influence the final merits decision, Art. 87 OG required immediate challenge.