Question juridique clé
Whether the federal complaint against the Aargau decision was admissible despite the unexhausted cantonal remedies and the prior Valais assessment
Solution extraite
The complaint was admissible; the second taxing canton may be challenged directly, and the earlier Valais assessment could be included.
Motifs extraits
In double-taxation matters, exhaustion of cantonal remedies is not required; timely filing against the second canton suffices, and Art. 89(3) OG allows inclusion of the first assessment.