anchor.diff:  ///    To learn more, see: https://docs.microsoft.com/en-us/dotnet/articles/fsharp/language-reference/xml-documentation
   
   
  -// Open namespaces using the 'open' directive.
  +// Open namespaces using the 'open' keyword.
   //
   // To learn more, see: https://docs.microsoft.com/en-us/dotnet/articles/fsharp/language-reference/import-declarations-the-open-keyword
   open System
  
positive.code: 
      /// Conditionals use if/then/elid/elif/else.
      ///
      /// Note that F# uses whitespace indentation-aware syntax, similar to languages like Python or Ruby.
      let sampleFunction3 x = 
          if x < 100.0 then 
              2.0*x*x - x/5.0 + 3.0
  
negative.code:     /// This is a list of all tuples containing all the numbers from 0 to 99 and their squares.
      let sampleTableOfSquares = [ for i in 0 .. 99 -> (i, i*i) ]
  
      // The next line prints a list that includes tuples, using '%A' for generic printing.
      printfn "The table of squares from 0 to 99 is:\n%A" sampleTableOfSquares
  
  
  /// Values in F# are immutable by default (save for Arrays).  They cannot be changed
  /// in the course of a program's execution unless explicitly marked as mutable.
  ///
  /// To learn more, see: https://docs.microsoft.com/en-us/dotnet/articles/fsharp/language-reference/values/index#why-immutable
  module Immutability =
  
      /// Binding a value to a name via 'let' makes it immutable.
      ///
      /// The second line of code fails to compile because 'number' is immutable and bound.
      /// Re-defining 'number' to be a different value is not allowed in F#.
      let number = 2
      // let number = 3
  
      /// A mutable binding.  This is required to be able to mutate the value of 'otherNumber'.
      let mutable otherNumber = 2
  
      // When mutating a value, use '<-' to assign a new value.
      //
      // Note that '=' is not the same as this.  '=' is used to test equality.
      otherNumber <- otherNumber + 1
  
  
  /// Much of F# programming consists of defining functions that transform input data to produce
  