Question Summary:
Writing a program guide

Question Detail:

I'm a summer student at a government job. One of my jobs involves writing a guide to using a program that evaluates the equivalent annual  cost of a building. It is used as a means of making purchasing decisions. I'm not making the calculations,  just showing how to use the program.  However, these evaluations involve interest. Is writing this guide sinful? I consulted a Sheikh and a mufti and they said it's ok,  since I'm not directly involved with the transaction. However, I'm still worried about it. 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
 
It is permissible for you to write the guide in reference.
 
And Allah Ta’āla Knows Best

Mufti Ebrahim Desai