I've defined the following instance: instance Arrow Circuit where arr f = Circuit $ \a -> (arr f, f a) first (Circuit cir) = Circuit $ \(b, d) -> let (cir', c) = cir b in (first cir', (c, d)) in the repl, how do I write "myCircuit = arr f" in such a way that ":t myCircuit" will return `Circui