User blog comment:Ynought/Extended degree function/@comment-35470197-20181230222231/@comment-36957202-20181231102436

>But applying 1.1.1 to \(C = (0)_{(0)}\), you obtain \(_{(0)}\) or \_{(0)}\), because you are just allowed to remove \(0\) (and a symbol left to the zero in this case).

These rules just apply to arrays with 2 or more entrys