BEx Formula Use of 'Logical And' and Calculation for Gross Margin

Question

HI Bex gurus.
Having an odd time with what should be a simple formula to handle the display of gross margin (GM). The goal here is to display GM% properly and the requirement is as follows
If GM <= 0 then 0.0
  Else
If GM > 0 and Sell > 0 then ( ( sell - cost /sell ) * 100 )
  Else
If GM >0 and Sell = 0 then 100
I am familiar with bex formulas and have referenced the help docs on booleans here -
Boolean Operators - SAP Business Explorer - SAP Library
But what is odd is that if I use a calculation or a CFK in the IF, THEN with a LOGICAL AND, the formula does not report correctly
If I put in a static value, like 77, the expected logic is followed.  I have tried making sure have extra parentheses and changing the order of the statement, to no avail!  I could use some extra brains on this puzzling matter, so you help is greatly appreciated and will award points!
Thanks
lee lewis
Here are the formulas in text and below screen shots.  Wish could copy and past formulas to and from editor!
GM%77
( ( ( 'Order GM' >0 ) AND ( Order Sell  >  0 ) ) == 1) * 77 + ( ( ( 'Order GM'> 0 ) AND ( Order Sell == 0 ) ) == 1) * 100 + ('Order GM' <= 0) *0.0
GM%
( ( ( 'Order GM' >0 ) AND ( Order Sell  >  0 ) ) == 1) * 'REF GM%' + ( ( ( 'Order GM' > 0 ) AND ( Order Sell == 0 ) ) == 1) * 100 + ('Order GM' <= 0) *0.0
'REF GM%
(order  sell - order cost /order sell ) * 100 )
GM%77
GM%

Answer 1

Shouldn't you change on of the brackets in your REF GM% ?
'REF GM%
(order  sell - order cost /order sell ) * 100 )
I would put that as
'REF GM%
(order  sell - order cost) /order sell  * 100 )
Not sure what you mean with those red arrows... but in both cases you would be dividing by 0 (order sell = 0).