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#light

type IProvideInt =
  abstract GetInt : unit -> int

type IProvideInt2 = 
  abstract GetInt2 : unit -> int

type Provider() =
  interface IProvideInt with
    member ipi.GetInt () = 1
  interface IProvideInt2 with
    member ipi.GetInt2 () = 2

let p = Provider()
printfn "Provided int1 of %d" ((p :> IProvideInt).GetInt())   
printfn "Provided int2 of %d" ((p :> IProvideInt2).GetInt2()) 

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let CreateDual f g = 
  { new obj()
    interface IProvideInt with
      member ipi.GetInt () = f ()
    interface IProvideInt2 with
      member ipi2.GetInt2 () = g () }

let y = CreateDual (fun () -> 6) (fun () -> 7)

// printfn "Provided int1 of %d" ((y :> IProvideInt).GetInt())
// printfn "Provided int2 of %d" ((y :> IProvideInt2).GetInt2())

let CreateDualAnotherAttempt f g = 
  { new IProvideInt with
      member ipi.GetInt () = f ()
    interface IProvideInt2 with
      member ipi2.GetInt2 () = g () }

let z = CreateDual (fun () -> 6) (fun () -> 7)

// printfn "Provided int1 of %d" ((z :> IProvideInt).GetInt())
// printfn "Provided int2 of %d" ((z :> IProvideInt2).GetInt2())

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objects.fs(32,32): error: Type constraint mismatch. The type 
    obj
is not compatibile with type
    IProvideInt.
The type 'obj' is not compatible with the type 'IProvideInt'