anchor.diff:  module Interfaces =
   
       let DOMException =
  -        Class "DomException"
  +        DOMClass "Exception"
           |+> Static [
                   "code" =? DOMExceptionType
  +                "message" =? T<string>
                   "name" =? T<string>
               ]
   
       let DOMStringList =
  -        Class "DomStringList"
  +        DOMClass "StringList"
           |+> Instance [
                   "length" =? T<int>
                   "contains" => T<string->bool>
  
positive.code:             ]
  
      let DOMRect =
          Class "DomRect"
          |+> Instance [
                  "x" =? T<double>
                  "y" =? T<double>
  
negative.code:             ]
  
      let DOMImplementationList =
          DOMClass "ImplementationList"
          |+> Instance [
                  "item" => T<int> ^-> DOMImplementation
                  "length" =? T<int>
              ]
  
      let DOMImpementationSource =
          DOMClass "ImplementationSource"
          |+> Instance [
                  "getDOMImplementation" =>
                      T<string> ^-> DOMImplementation
  