Equation Icon  j (0) j j (0) ∂A-- (0) ∂u--- ∂F-- (0) A 0(t,x) = A (t,x,u (t,x )), B0(t,x) = ∂u (t,x,u (t,x))∂xj + ∂u (t,x,u (t,x)).(3.122 )