=+(31.8) and the ideas in Example 31.1 to show that f is nowhere differentiable.

'A Lipschitz condition of order @ holds at x if F(x + h) - F(x) - O(|h|") as h -> 0; for @ > 1 this implies F'(x) =0, and for 0 <@ < 1 it is a smoothness condition stronger than continuity and weaker than differentiability.