I'm surprised you refuse to give us "your" definition, does it only include bobbers? Your making me guess and the more I guess the more likely I'll be wrong, your choice I suppose. Also, if you use a floating hopper with a hook in it your dry fly fishing, unless you have another fly somewhere under the water. Then you'd be fishing, fly fishing, two flies at a time. That fits into my definition of fly fishing with 2 flies, what's your definition?