Art. 59 BV; evidentiary decree concerning disputed facts relevant to jurisdiction and prerogation; admissibility of federal constitutional complaint. A cantonal order directing proof of contested allegations bearing on jurisdiction does not, by itself, constitute a final assertion of judicial competence or an enforceable submission to the cantonal forum. Such an interlocutory evidentiary measure is not immediately challengeable by constitutional complaint. However, allegations that a party assented to the forum and appointed a representative may be legally relevant to prorogation and, if proved, can support jurisdiction under federal practice (consid. 2). The remedy is therefore premature until a decision on competence is actually rendered.