Art. 46 BV; double taxation and federal competence: Bundesgericht intervenes only where the tax laws of two or more cantons lay claim to the taxation of the same object, so that an intercantonal conflict exists. Where the dispute concerns exclusively the application of a cantonal tax law to a taxpayer domiciled in that canton, no constitutionally relevant double taxation is present and the federal court lacks jurisdiction to entertain the complaint (consid. 1).