function x=inf_solve(A, b)

    n = length(b);
    x=zeros(n, 1);  
    x(1)=b(1)/A(1, 1);
    for i=2:n
        somma=0;
        for j=1:i-1
           somma=somma + A(i, j)*x(j); 
        end
        x(i)=(b(i)-somma)/A(i,i);
    end