anchor.diff:                      fragSelection
                   | None -> [])
   
  -    let private getOperationDefinitions (ast : Document) = ast.Definitions |> List.choose (function | OperationDefinition x -> Some x | _ -> None)
  -
  -    let private getFragmentDefinitions (ast : Document) = ast.Definitions |> List.choose (function | FragmentDefinition x -> Some x | _ -> None)
  +    let private getOperationDefinitions (ast : Document) = 
  +        ast.Definitions
  +        |> List.choose (function | OperationDefinition x -> Some x | _ -> None)
  +
  +    let private getFragmentDefinitions (ast : Document) = 
  +        ast.Definitions 
  +        |> List.choose (function | FragmentDefinition x -> Some x | _ -> None)
   
       let internal getValidationContext (schemaInfo : SchemaInfo) (ast : Document) =
           let fragmentDefinitions = getFragmentDefinitions ast
  
positive.code:         let argumentsValid =
              selection.Field.Arguments
              |> collectResults (fun arg ->
                  let args =
                      metaTypeFields.TryFind(selection.Field.Name)
                      |> Option.orElseWith (fun () -> selection.InputValues |> Option.map (Array.map (fun x -> x.Name)))
                  match args |> Option.bind (Array.tryFind (fun x -> x = arg.Name)) with
                  | Some _ -> Success
                  | None -> AstError.AsResult(sprintf "Field '%s' of type '%s' does not have an input named '%s' in its definition." selection.Field.Name selection.FragmentOrParentType.Name arg.Name, selection.Path))
          let directivesValid =
  
negative.code:     type SelectionInfo =
          { /// Contains the information about the field inside the selection.
            Field : Field
            /// Contains the selection of the field (in case the field is an Object, Interface, or Union type).
            mutable SelectionSet : SelectionInfo list
            /// Contains the reference to tye field type in the schema.
            FieldType : IntrospectionTypeRef option
  