Four sections in the XQuery 1.0 spec:
    3.7.1.1 Attributes
    3.7.3.2 Computed Attribute Constructors
    3.7.3.5 Computed Processing Instruction Constructors
    3.7.3.6 Computed Comment Constructors
have substantially the same chunk of text, for converting an XDM sequence
into a string value:

   1.  Atomization is applied to the [input], converting it to a
       sequence of atomic values.
   2.  If the result of atomization is an empty sequence, the [output]
       is the zero-length string. Otherwise, each atomic value in the
       atomized sequence is cast into a string.
   3.  The individual strings resulting from the previous step are merged
       into a single string by concatenating them with a single space
       character between each pair. The resulting string [is the output].

Could these be abstracted into a single concept/process for 1.1?