anchor.diff:      /// They are used extensively in F# code to represent the cases where many other
       /// languages would use null references.
   
  -    type Customer = { zipCode : decimal option }
  +    type Customer = { ZipCode : decimal option }
   
       /// Abstract class that computes the shipping zone for the customer's zip code, 
       /// given implementations for the 'getState' and 'getShippingZone' abstract methods.
       [<AbstractClass>]
       type ShippingCalculator =
  -        abstract getState : decimal -> string option
  -        abstract getShippingZone : string -> int
  +        abstract GetState : decimal -> string option
  +        abstract GetShippingZone : string -> int
   
           /// Return the shipping zone corresponding to the customer's ZIP code
           /// Customer may not yet have a ZIP code or the ZIP code may be invalid
  -        member this.customerShippingZone(customer : Customer) =
  -            customer.zipCode |> Option.bind this.getState |> Option.map this.getShippingZone
  +        member this.CustomerShippingZone(customer : Customer) =
  +            customer.ZipCode |> Option.bind this.GetState |> Option.map this.GetShippingZone
   
   
   
  
positive.code:     /// Computes the greatest common factor of two integers. 
      //  Since all of the recursive calls are tail calls, the compiler will turn the function into a loop,
      //  which improves performance and reduces memory consumption.
      let rec greatestCommonFactor a b =                       
          if a = 0 then b
          elif a < b then greatestCommonFactor a (b - a)           
          else greatestCommonFactor (a - b) b
  
      /// Computes the sum of a list of integers using recursion.
  
negative.code: module PatternMatching = 
  
      /// A record for a person's first and last name
      type Person = {
          First : string
          Last  : string
      }
  