You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: diff.m
    path of file: ./repos/MATLABAutoDiff/@myAD
    
    the code of the file until where you have to start completion: function x = diff(x,varargin)

    
function x = diff(x,varargin)
  % Edited by SeHyoun Ahn, Jan 2016

  % In Package myAD - Automatic Differentiation
  % by Martin Fink, June 2006
  % martinfink 'at' gmx.at
  aux = size(x.values);
  l = size(x.derivatives,2);
  if nargin == 1
    reduction = find(aux>1);
    reduction = reduction(1);
    x.values = diff(x.values);
    x.derivatives = reshape(x.derivatives,aux(reduction),prod(aux)/aux(reduction)*l);
    x.derivatives = diff(x.derivatives);
    x.derivatives = reshape(x.derivatives,(aux(reduction)-1)*prod(aux)/aux(reduction),l);
  elseif nargin == 2
    reduction = find(aux>1);
    reduction = reduction(1);
    x.values = diff(x.values);
    x.derivatives = reshape(x.derivatives,aux(reduction),prod(aux)/aux(reduction)*l);
    x.derivatives = diff(x.derivatives);
    x.derivatives = reshape(x.derivatives,(aux(reduction)-1)*prod(aux)/aux(reduction),l);
    if varargin{1} > 1
      x = diff(x,varargin{1}-1);
    end