m:annotation-xml, m:apply, m:bind, m:cerror, m:condition, m:degree, m:domainofapplication, m:interval, m:lambda, m:list, m:logbase, m:lowlimit, m:matrix, m:matrixrow, m:momentabout, m:otherwise, m:piece, m:semantics, m:set, m:uplimit and m:vector
This element must not contain text.
This element may contain the following children: m:otherwise and m:piece
http://www.w3.org/1998/Math/MathML