English
The support of f equals the symmetric-image form: extChartAt I c .symm '' (ball (extChartAt I c c) f.rOut ∩ range I).
Русский
Опорное множество f совпадает с симметрическим образом extChartAt I c .symm '' (ball (extChartAt I c c) f.rOut ∩ range I).
LaTeX
$$$\operatorname{support}(f) = (\operatorname{extChartAt} I c).\mathrm{symm} '' (\mathrm{ball}(\operatorname{extChartAt} I c c, f.rOut) \cap \mathrm{range}\ I).$$$
Lean4
theorem support_eq_symm_image : support f = (extChartAt I c).symm '' (ball (extChartAt I c c) f.rOut ∩ range I) := by
rw [f.support_eq_inter_preimage, ← extChartAt_source I, ← (extChartAt I c).symm_image_target_inter_eq', inter_comm,
ball_inter_range_eq_ball_inter_target]