% -*- texinfo -*-
% @deftypefn {Function File} {[@var{C}]} = BIM2Areaction(@var{mesh}, @var{delta}, @var{zeta})
%
% Builds the matrix for the discretization of the LHS
% of the equation
% @iftex
% @tex
% $ \delta \zeta u = f $
% @end tex
% @end iftex
% @ifnottex
% @var{delta} * @var{zeta} * u = f
% @end ifnottex
%
% Input:
% @itemize @minus
% @item @var{mesh}: list of mesh nodes coordinates
% @item @var{delta}: elemental values of a piece-wise constant function.
% @item @var{zeta}: nodal values of a piece-wise linear conforming function.
% @end itemize
%
% @seealso{BIM1Arhs, BIM1Aadvdiff}
% @end deftypefn