For the frontier vertices V₅ and V₆ adjacent to V₄, updated distances are:

dist(V₀, V₅) = dist(V₀, V₄) + dist(V₄, V₅) = 8 + 3 = 11

dist(V₀, V₆) = dist(V₀, V₄) + dist(V₄, V₆) = 8 + 2 = 10

But wait! dist(V₀, V₅) was already 9!

So we should not change this distance since the update through the new known vertex does not give a smaller value.