MDX Function and Operator Reference - Professional SQL Server Analysis Services 2005 with MDX - page 1037

TupleToStr( ([Time].[1997], [Customer].[All
Customers]) )
Trying to create an empty tuple with () will result in a syntax error. In Analysis
Services 2005, you can create an essentially empty tuple with null member
references. For example (null, null) specifies an empty tuple.
Constructing Sets
{ tuple or set [, tuple or set . . . ] }
Sets can be explicitly constructed by enclosing one or more tuples or sets
with the same dimensionality within curly braces, "{" and "}." Each tuple or set
specification must be separated from the next by a comma. For example, the
following are all sets:
{ [Time].[1997] }
{ ([Time].[1997], [Customer].[All Customers]) }
{ [Time].[All Time], [Time].[Year].Members,
{ [Time].[Quarter].Members } }
The first two are sets of one tuple each, and the last one is a set composed of
one member and two sets, in order. Note that in the last example, one set is
syntactically inside the other, and the inner one is also enclosed in curly
braces. This is not required, and it does not affect the interpretation in any
way. Although an empty set is not usually of much practical use, it may be
created with an empty pair of curly braces: {}
member : member
This operator constructs a set from two members and uses the two members
as endpoints. The two members must be on the same level; if they are not, a
parse error will occur. If you use the database ordering of the members in the
dimension, all members between the endpoints will be included. It is not an
error for the two members to be the same (that is, {[Time].[2006] :
[Time].[2006]}).
In Microsoft Analysis Services 2005, and 2000, if the member on the
righthand side of the colon is earlier in the database ordering than the mem-
ber on the left, a range is constructed from the member on the right to the
member on the left (as though the members were flipped around the colon;