English
The co-polarization In map coincides with the CoPolarization map when restricted appropriately.
Русский
Ко-поляризация In совпадает с CoPolarization при соответствующем ограничении.
LaTeX
$$$P.CoPolarizationIn\\ S x = P.CoPolarization x$$$
Lean4
theorem PolarizationIn_eq (x : P.rootSpan S) : P.PolarizationIn S x = P.Polarization x :=
by
simp only [PolarizationIn, LinearMap.coeFn_sum, LinearMap.coe_comp, Finset.sum_apply, comp_apply,
LinearMap.toSpanSingleton_apply, Polarization_apply]
refine Finset.sum_congr rfl fun i hi ↦ ?_
rw [algebra_compatible_smul R (P.coroot'In S i x) (P.coroot i), algebraMap_coroot'In_apply]