(1) Except in a mandatory appeal, the supreme court may at any time, on its own motion and without notice or on such notice as it may order, dispose of a case, or any question raised therein, summarily. An order of summary affirmance under this rule may be entered when (a) no substantial question of law is presented and the supreme court does not disagree with the result below, or (b) the case includes the opinion of the trial court, which identifies and discusses the issues presented and with which the supreme court does not disagree, or (c) the case includes the decision of the administrative agency appealed from, and no substantial question of law is presented and the supreme court does not find the decision unjust or unreasonable, or (d) other just cause exists for summary affir