I'm trying to figure out what this one symbol was I saw. I also have a guess that I would like to see if is correct. I saw a double integral with a circle connecting the two. What does this mean? Here is my guess. Is it used when dealing with Stoke's Theorem? Since ∫F°dS =∫∫ curl(F)°dS (Both F and S are vectors, just don't know how to make the arrow) can you write the integrals in ∫∫curl(F)°dS with a circle connecting the two if the first integral ∫F°dS is simple, closed, has continuous first order partial derivatives and is positively oriented? Is that what I saw? Just someone connecting the double integral in Stoke's Theorem with a circle to show the curve is positively oriented and meets all the other required criteria? Thanks.