ddMCL_k)_ij = <d^2/dx_i dx_j A_k(x,Y), Umlt>|
%
% This offers an alternative to |mconhess()| in order to reduce a significant
%   overhead connected with repeated calls to |mconhess()|. Examples how to
%   implemented are |modules/BMI/bmi_mconlagrhess.m| or equivalent in |PMI|.
%
%
% The meaning of the last (optional) argument |pointchanged|: if
% |pointchanged = 1| then the values of |x,Y| have changed and this call is
% the first one supplying the new values; if |pointchanged = 0| we supply
% th