[LAU] logical AND in Faust

Hi, I tried to post this to faust-users-list, but since I changed my email-adress this was refused. Now, after spending a week of "awaiting moderator approval", I decided to post my question here, and I hope that some of the faust-guys might be around. I have a problem understanding this piece of faust-code: index( n ) = &( n - 1 ) ~ + ( 1 ); It is from the faust-soft-computing.pdf. I do understand that it works like a counter and I think it should jump back to 0 when it reaches n - 1. But what exactly is the logical AND operator doing? In the quick reference it is sayed, that primitives behave like their C counterpart. O.k. I don't have any experience in C, but I realy tried to figure this out. To me it seemed, that the "&" operator in C would give back the smaller value of the two compared. So in this case it would give pack the line from 0 to n-1 and then continue with streaming n-1. But that would not make any sense if it is used in a delay-line, to calculate the read/write index, does it? Please correct me if I missunderstood something and thank you for help. Kind regards, Bjoern