I would write the condition like this: present = ifc(a and b,"Y","N"); ... View more

Thank you so much,i got desirable result! ... View more

@Andrew15 wrote: Yes it's homework task,and i am not allowed to use Reverse tool. Well then I think your instructor has created a stupid problem. There are plenty of other things he could have asked you to program that don't have a built-in tool. One of the benefits of SAS (and most programming languages) is that commonly needed tools are provide so you don't have to create your own. I hope that if you ever have a need for this outside of this class, you will use the REVERSE function. ... View more