How can I add another row to a Multi-Row Expression?

[hellyars]

I need a little help modifying an expression

Current Scenario

I have a data set that includes Name and cost type (CT) and amount for a given year (2017 $).  

For any cost type Bs, I need to add B to A.  (B is always negative.)  I use the following expression with the Multi-Row Tool set to create new field. 

if [Row+1:CT] = 'B' then [2017 $] + [Row+1:2017 $] else [2017 $] endif 

Name	CT	2017 $
Jeep	A	555
G-Wagon	A	1800
G-Wagon	B	-100
G-Wagon	C	200
HMMWV	A	800
HWMMV	B	-400
Unimog	A	700

Question

Now I need to add E to the expression.  Like B, E is always negative.  But, its still A+B+E.  

How do I mod the expression to include E?

Name	CT	2017 $
Jeep	A	555
G-Wagon	A	1800
G-Wagon	B	-100
G-Wagon	E	-500
G-Wagon	C	200
HMMWV	A	800
HWMMV	B	-400
Unimog	A	700

[hellyars]

Okay, I tried the following...

if [Row+1:CT] = 'B' then [2017 $] + [Row+1:2017 $]
elseif [Row+1:CT] ='B' and [Row+2:CT] ='E' then [2017 $] + [Row+1:2017 $] + [Row+2:2017 $]
else [2017 $]
endif

It does not work with the"if" and "else if" expressions work on their own, BUT they don't work together.  How do I do this? 

I need to account for scenarios where just As exist, A and Bs exist and A, B and Es exist.

[hellyars · Accepted solution]

I think I got it.  Hopefully it will translate to the real data/worklow.

if
[Row+1:CT] = 'B' and [Row+2:CT]!='E' then [2017 $] + [Row+1:2017 $]

elseif
[Row+1:CT] ='B' and [Row+2:CT] ='E' then [2017 $] + [Row+1:2017 $] + [Row+2:2017 $]
else [2017 $]
endif