I am trying to pick through Karp's paper on computational complexity "reducibility among combinatorial problems". In it he defines a deterministic algorithm. I cannot understand the line:

a finite aphabet [delta symbol] such that [delta symbol]* [chevron symbol] R = [null set symbol]

Where I put chevron symbol is an inverted v (like logical and). What does this mean. An intersection symbol is shown later on so I assume that intersection symbol was available and would have been used if that was appropriate here.

Of course one cannot google on a symbol whose name one does not know.

Bob.