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:     |> should equal ([1; 2; 3], [4; 5])
  
  [<Test>]
  [<ExpectedException(typeof<System.ArgumentException>, ExpectedMessage = "The number of items to take from the list is greater than the length of the list.\r\nParameter name: count")>]
  let ``{chop_list i [x1;_;xn]} fails with if {i} is greater than the length of the list``() =
  
      chop_list 4 [1;2;3] 
      |> ignore
  
  [<Test>]
  [<ExpectedException(typeof<System.ArgumentException>, ExpectedMessage = "The number of items to take from the list is negative.\r\nParameter name: count")>]
  let ``{chop_list i [x1;_;xn]} fails with if {i} is negative``() =
  
      chop_list -1 [1;2;3] 
  