RE: Using LATERAL for intermediate results

I just saw a discussion about the LATERAL syntax in SQL. So, its function
is to allow a joined table to take into account values from previously
listed tables. As I googled around, I saw some other databases using it in
a way that DB2 for i doesn't allow, so I wonder if there is a way to make
it work that someone else might have found.


Simple example that works in another database, but not ours:

select CUST, AMOUNT, HalfAmount
from INVOICE,
lateral (select AMOUNT/2 as HalfAmount) T1


This sort of works, but you can't refer to HalfAmount in another
calculation, which is the point of this excercise:
select *
from INVOICE,
lateral (values(INVOICE.ramt/2)) halflist