anchor.diff:      |> should equal 4
   
   [<Test>]
  -[<ExpectedException(typeof<System.Exception>, ExpectedMessage = "find")>]
  -let ``{find p [x1;_;xn]} fails with if no element satisfies the predicate``() =
  +let ``{find p [x1;_;xn]} fails with None if no element satisfies the predicate``() =
       
       find (fun x -> x > 5) [1;2;3;4;5]
  -    |> ignore
  +    |> should equal None
   
   (* tryfind tests *)
   
  
positive.code:     |> should equal 1
  
  [<Test>]
  [<ExpectedException(typeof<System.Exception>, ExpectedMessage = "check")>]
  let ``{check p x} fails if the predicate {p} yields {false} when applied to the value {x}``() =
  
      check ((=) 1) 2
      |> ignore
  
  (* funpow tests *)
  
  
negative.code: (* applyd tests *)
  
  [<Test>]
  let ``{applyd f g x} returns {Some (f x)} if {f} is defined on {x}``() =
  
      applyd (1 |=> 2) (fun x -> Some x) 1 // note that |=> is defined later in Lib module
      |> should equal (Some 2)
  
  [<Test>]
  let ``{applyd f g x} returns {Some (g x)} is {f} if undefined on {x}``() =
  
      applyd undefined (fun x -> Some x) 1
      |> should equal (Some 1)
  
  (* apply tests *)
  
  [<Test>]
  let ``{apply f x} returns {Some (f x)} if {f} is defined on {x}``() =
  
      apply (1 |=> 2) 1 // note that |=> is defined later in Lib module
      |> should equal (Some 2)
  
  [<Test>]
  let ``{apply f x} returns None if {f} is undefined on {x}``() =
  
      apply undefined 1
      |> should equal None
  
  (* tryapplyd tests *)
  
  