   function [Ak,     userdata] = mconfun(x,Y,k,userdata) 
%     function [dAki,   userdata] = mcongrad(x,Y,k,i,userdata) 
%     function [ddAkij, userdata] = mconhess(x,Y,k,i,j,userdata)
%     function [ddMCLk, userdata] = mconlagrhess(x,Y,k,Umlt,userdata)
% 
% These should return:
%
% * a value of the |k|-th matrix constriant (|k=1..NANLN+NALIN|)
%   as a dense or sparse symmetric matrix |Ak|,
% * a derivative of the |k|-th matrix constraint (|k=1..NANLN+NALIN|)
%   w.r.t. |i|-th variable (|i=1..