Equation Icon  (k+1) ∑n j (k) ∂ (k+1) (k) n ut = A (t,x,u )--j-u + F (t,x, u ) + δF (t,x), x ∈ ℝ , 0 ≤ t ≤ T, (3.123 ) j=1 ∂x (k+1) n u (0,x) = f(x) + δf(x), x ∈ ℝ , (3.124 )