MDX set question

Question

I have this MDX query, part 1 or part 2 returns exact same result. I can understand part 2, can someone explains part 1? I am overwhelmed with tuple, set etc. I don't need explanation on basic concepts,  just need a clarification on what's happening
in part 1? I mean how the () part converted to many rows(tuples) in result? Thanks.
select 
[Measures].[Till button sold value]
,[Measures].[Till button units]
,[Measures].[Till button baskets]
on columns
,non empty
{-- part 1
[Branch].[Branch].[Carlisle]
,[Till Button].[Till Button].[11]
,[Time].[Day].&[20140202]: [Time].[Day].&[20140208]
,[Products].[Product code].[Product code]
,[Sales order details].[Receipt No].[Receipt No]
-- part 2
//{[Branch].[Branch].[Carlisle]}
//*{[Till Button].[Till Button].[11]}
//*{[Time].[Day].&[20140202]: [Time].[Day].&[20140208]}
//*{[Products].[Product code].[Product code]}
//*{[Sales order details].[Receipt No].[Receipt No]}
on rows
from [Rmis]

Answer 1

Hi,
From my understanding part one is simply slicing those measures by that set. It should return an aggregated record for the location in the cube specified. Here is a clear example using Adventure Works cube. I want to bring back Internet Sales for
05/01/2007 where the currency is Dollar for product 346.
The query below will return one record, this record is the aggregated data for that specific location in the cube.
SELECT
{[Measures].[Internet Sales Amount]} ON COLUMNS,
NON EMPTY
([Date].[Date].&[20050701], [Product].[Product].&[346],[Destination Currency].[Destination Currency].&[US Dollar]) ON ROWS
FROM [Adventure Works]
Note it looks like your statement is bringing back the aggregated total for all receipt numbers and product codes for a specific Branch and Till Button (ID of 11) for 2/8/2014.
No part 1 returns many rows not one row. Like what i have said part 1 and part 2 returns exact same result, which is cross join of those sets (applied non empty afterwards).