Help in expression

[ali_hijazi]

Hello
I have a pivot table with several expressions
I will show you 2 expressions 1 and 2 written in two different ways but they return the same correct result

expression 1 is not distributed on any dimension
while expression 2 is distributed on any dimension

but expression 2 is very slow when used with the remaining expressions in the pivot table
while expression 1 is much faster

Expression1:
{
$
-<[Parent PRoject Portfolio Level 1 ID]={1},[Portfolio Level 1 ID]={18}>
-<[Parent PRoject Portfolio Level 1 ID]={1},[Portfolio Level 3 ID]={37}>
}
sum(SPENT_MANDAYS)

Expression 2:

(
sum(SPENT_MANDAYS)
-
{<[Parent PRoject Portfolio Level 1 ID]={1},[Portfolio Level 1 ID]={18}>}
sum(SPENT_MANDAYS)
-
{<[Parent PRoject Portfolio Level 1 ID]={1},[Portfolio Level 3 ID]={37}>}
sum(SPENT_MANDAYS)
)

kindly advise on why expression 1 is alwys under null scenario type

[ali_hijazi]

Well I've been working on Qlik since 2011 (QlikView)

Whenever I encounter such weird cases no one explains why whether on community or via support cases 

Ok I can add a composite field, but what if the script is not supposed to be changed meaning that I only can work on the UI which is the current situation? I assume that exclusion doesn't work well in Qlik