theorem
pointwiseGrowthFunction_eq_zero_of_nonpos
{X : Type u}
[MetricSpace X]
(f : X → ℝ)
(xBar : X)
(t : ℝ)
(ht : t ≤ 0)
:
pointwiseGrowthFunction f xBar t = 0
Proposition 3.34 (1): the pointwise growth function ω_f(xBar; t) vanishes for every
nonpositive radius t.
theorem
pointwiseGrowthFunction_monotone
{X : Type u}
[MetricSpace X]
(f : X → ℝ)
(xBar : X)
:
Monotone (pointwiseGrowthFunction f xBar)
Proposition 3.34 (2): the function t ↦ ω_f(xBar; t) is monotone nondecreasing in the
radius parameter.
theorem
sub_le_pointwiseGrowthFunction_dist
{X : Type u}
[MetricSpace X]
(f : X → ℝ)
(xBar x : X)
:
↑(f x) - ↑(f xBar) ≤ pointwiseGrowthFunction f xBar (dist x xBar)
Proposition 3.34 (3): every increment f x - f xBar is bounded above by the pointwise growth
function evaluated at the distance from x to xBar.