For each of the following definitions, say whether it is a simple value or a function and if a function, what is the function signature? If in doubt, run them in the F# Interactive Tool to find out!

let testA = 2 let testB x = 2 + x let testC x = 2.0 + x let testD = "hello" let testE = printfn "hello" let testF () = 42 let testG () = printfn "hello" let testH x = String.length x let testI x = sprintf "%i" x let testJ x = printfn "%i" x let testK x = printfn "x is %f" x; x // return x let testL (f:int -> string) x = f x let testM f (x:int) :string = f x let testN x :string = x 1 // hint: what does :string modify? let testO x = 1 let testP x = x 1 // hint: what kind of thing is x? let testQ x y = x let testR x y z = z let testS x = x=x let testT f = (f 1) + 2 let testU f = sprintf "%i" (f 1) let testV f = f() + 2 let testW x = fun y -> y * x let testX x y = y * x let testY = fun x y -> y * x let testZ f x = (f 1) + x