Last week set analysis

[#1]

How can i use the Weekstart function within a set analysis, so that only the data for last week is included? (I do not mean the last 7 days, i mean the preceding working week.) In this case, I can't adjust my master calendar so have to make do with the CalendarDate field.

This is my expression

=sum({$<Book={"EM MATCH"}>}PRICE)

I can't get my head round the correct syntax

[MK_QSL]

I have checked and both giving same result.

Please check enclosed file....