The top-level element information item in a CellML infoset MUST be an
element information item in the CellML namespace, with local name
model. This element information item is referred to in this
specification as the model element.
Every model element MUST contain a name attribute in the empty
namespace. The value of the name attribute MUST be a valid CellML
identifier, and SHALL be interpreted as a unique identifier for the
CellML infoset.
A model element MAY contain zero or more additional specific
information item children, each of which MUST be of one of the
following types: