anchor.diff:  
   namespace Microsoft.FSharp.Compiler.SourceCodeServices
   open System
  +open System.IO
   open System.Collections.Generic
   
   open Microsoft.FSharp.Compiler 
  +open Microsoft.FSharp.Compiler.Ast
  +open Microsoft.FSharp.Compiler.Driver
  +open Microsoft.FSharp.Compiler.ErrorLogger
   open Microsoft.FSharp.Compiler.Range
   open Microsoft.FSharp.Compiler.TcGlobals
   open Microsoft.FSharp.Compiler.NameResolution
  
positive.code:     /// <param name="options">The options for the project or script, used to determine active --define conditionals and other options relevant to parsing.</param>
      member GetBackgroundCheckResultsForFileInProject : filename : string * options : FSharpProjectOptions -> Async<FSharpParseFileResults * FSharpCheckFileResults>
  
      /// <summary>
      /// Try to get type check results for a file. This looks up the results of recent type checks of the
      /// same file, regardless of contents. The version tag specified in the original check of the file is returned.
  
negative.code: type IsResultObsolete = 
      | IsResultObsolete of (unit->bool)
  
  module internal CompileHelpers =
      val mkCompilationErorHandlers : unit -> List<FSharpErrorInfo> * ErrorLogger * ErrorLoggerProvider
      val tryCompile : errorLogger:ErrorLogger -> f:(Exiter -> unit) -> int
      val compileFromArgs : argv:string [] * tcImportsCapture:(TcImports -> unit) option * dynamicAssemblyCreator:(TcConfig * AbstractIL.IL.ILGlobals * ErrorLogger * string * string option * AbstractIL.IL.ILModuleDef * SigningInfo -> unit) option -> FSharpErrorInfo [] * int
      val compileFromAsts : asts:ParsedInput list * assemblyName:string * outFile:string * dependencies:string list * noframework:bool * pdbFile:string option * executable:bool option * tcImportsCapture:(TcImports -> unit) option * dynamicAssemblyCreator:(TcConfig * AbstractIL.IL.ILGlobals * ErrorLogger * string * string option * AbstractIL.IL.ILModuleDef * SigningInfo -> unit) option -> FSharpErrorInfo [] * int
      val dynamicAssemblyCreator<'a,'b,'c,'d,'e> : debugInfo:bool * tcImportsRef:TcImports option ref * execute:'a option * assemblyBuilderRef:Reflection.Emit.AssemblyBuilder option ref -> _tcConfig:'b * ilGlobals:AbstractIL.IL.ILGlobals * _errorLogger:'c * outfile:string * _pdbfile:'d * ilxMainModule:AbstractIL.IL.ILModuleDef * _signingInfo:'e -> unit
      val setOutputStreams : execute:(#TextWriter * #TextWriter) option -> unit
  
  
  /// The result of calling TypeCheckResult including the possibility of abort and background compiler not caught up.
  [<RequireQualifiedAccess>]
  type FSharpCheckFileAnswer =
  