function F = tropical2(A_1,A_2,L)
m     = size(L,1); 
[X,Y] = meshgrid (A_1,A_2); 
F     = L(1,1)*X + L(1,2)*Y + L(1,3); 
for k = 2:m
    Faux = L(k,1)*X + L(k,2)*Y + L(k,3);
    F    = max(F,Faux); 
end    
endfunction
