function [m] = mult(A,b)
%tailored multiplication for Laplace matrix for 2-D domain
	m(1)=                          A(1,1)*b(1)+ A(1,2)*b(2)+ A(1,4)*b(4);
   m(2)=             A(2,1)*b(1)+ A(2,2)*b(2)+ A(2,3)*b(3)+ A(2,5)*b(5);
   m(3)=             A(3,2)*b(2)+ A(3,3)*b(3)+              A(3,6)*b(6);
   m(4)=A(4,1)*b(1)+              A(4,4)*b(4)+ A(4,5)*b(5)+ A(4,7)*b(7);
   m(5)=A(5,2)*b(2)+ A(5,4)*b(4)+ A(5,5)*b(5)+ A(5,6)*b(6)+ A(5,8)*b(8);
   m(6)=A(6,3)*b(3)+ A(6,5)*b(5)+ A(6,6)*b(6)+              A(6,9)*b(9);
   m(7)=A(7,4)*b(4)+              A(7,7)*b(7)+ A(7,8)*b(8);
   m(8)=A(8,5)*b(5)+ A(8,7)*b(7)+ A(8,8)*b(8)+ A(8,9)*b(9);
   m(9)=A(9,6)*b(6)+ A(9,8)*b(8)+ A(9,9)*b(9);
   m=m';
return