Scheduled Transactions, Variables and Formulas

[Cheryl Wheeler]

I am playing with variables and formulas in scheduled transactions. I 
created a test SX using the example shown here 
(https://wiki.gnucash.org/wiki/Scheduled_Transactions#Bank_Account_Interest). 
When I tried to save the SX, GnuCash gave me an error message saying 
that it couldn't parse the formula. After some experimentation, I found 
that the problem seems to be the use of the variable "i" when passed as 
a parameter to the function "computeInterestIncrement". If I change i to 
a numeral, then the formula parses; if I use i alone (no function call), 
it parses.

The example in the wiki is from 2005. Assuming that it once worked, have 
there been intentional changes such that it is no longer expected to 
work, or would this be a bug? I am using GnuCash 2.6.15 on Windows 7.