anchor.diff:                  | SynMemberDefn.AutoProperty(_attributes, _isStatic, _id, _type, _memberKind, _memberFlags, _xmlDoc, _access, expr, _r1, _r2) ->
                       walkExpr expr
                   | SynMemberDefn.Interface(interfaceType, members, _range) ->
  -                    if inRange interfaceType.Range pos then
  +                    if rangeContainsPos interfaceType.Range pos then
                           Some(InterfaceData.Interface(interfaceType, members))
                       else
                           Option.bind (List.tryPick walkSynMemberDefn) members
  
positive.code:                     None
  
          and walkSynMemberDefn (memberDefn: SynMemberDefn) =
              if not <| inRange memberDefn.Range pos then
                  None
              else
                  match memberDefn with
  
negative.code:                 | SynExpr.ObjExpr(ty, baseCallOpt, binds, ifaces, _range1, _range2) -> 
                      match baseCallOpt with
                      | None -> 
                          if rangeContainsPos ty.Range pos then
                              Some (InterfaceData.ObjExpr(ty, binds))
                          else
                              ifaces |> List.tryPick (fun (InterfaceImpl(ty, binds, range)) ->
                                  if rangeContainsPos range pos then 
                                      Some (InterfaceData.ObjExpr(ty, binds))
                                  else None)
                      | Some _ -> 
  