anchor.diff:      // Exercise system
       let result = fixture.Create<AbstractType>()
       // Verify outcome
  -    Assert.IsAssignableFrom<AbstractType>(result)
  +    verify <@ typeof<AbstractType>.IsAssignableFrom(result.GetType()) @>
       // Teardown
   
   [<Fact>]
  
positive.code:     // Exercise system
      let result = fixture.Create<IInterface>()
      // Verify outcome
      Assert.IsAssignableFrom<IInterface>(result)
      // Teardown
  
  [<Fact>]
  
negative.code:     // Exercise system
      let result = fixture.Create<AbstractTypeWithConstructorWithMultipleParameters<int, int>>()
      // Verify outcome
      verify <@ not <| (Unchecked.defaultof<int> = result.Property1) @>
      verify <@ not <| (Unchecked.defaultof<int> = result.Property2) @>
      // Teardown
  