Missouri constitution
Article V: judicial department
Section 7

The
supreme court may sit en banc or in divisions as the court may determine. Any district
of the court of appeals may sit at such places within the district and in divisions as the
judges of such district may determine. Each division of the supreme court or of the
court of appeals shall be composed of not less than three judges, at least one of whom
shall be a regular judge of the court. A majority of a division shall constitute a quorum
thereof, and all orders, judgments, and decrees of a division, as to causes and matters
pending before it, shall have the force and effect of those of the court.