anchor.diff:      with e -> 
         None
   
  -
     let BackupInstallationProbePoints = 
         [ // prefer the latest installation of Mono on Mac
           "/Library/Frameworks/Mono.framework/Versions/Current"
  
positive.code:       if String.IsNullOrEmpty(s) then None
        else Some(s)
  
        
      
  
    // MaxPath accounts for the null-terminating character, for example, the maximum path on the D drive is "D:\<256 chars>\0". 
    // See: ndp\clr\src\BCL\System\IO\Path.cs
  
negative.code:         // This only works for .NET 2.0 - 4.0. To target Silverlight or Portable you'll need to use a direct reference to
          // the right FSharp.Core.dll.
          let result =
              //early termination on Mono, continuing here results in failed pinvokes and reg key failures ~18-35ms
              if Environment.runningOnMono then None else
              match reqLangVersion, targetFramework with 
              | FSharp_2_0, x when (x = FSharpTargetFramework.NET_2_0 || x = FSharpTargetFramework.NET_3_0 || x = FSharpTargetFramework.NET_3_5) -> 
                  tryRegKey @"Software\Microsoft\.NETFramework\v2.0.50727\AssemblyFoldersEx\Microsoft Visual F# 4.0"
  