English
If the coefficients were constant, the radius would be infinite.
Русский
Если коэффициенты постоянны, радиус бесконечен.
LaTeX
$$$p.radius = \\infty$ if $p_n$ are constant in n.$$
Lean4
theorem radius_compContinuousLinearMap_le [Nontrivial F] (p : FormalMultilinearSeries 𝕜 F G) (u : E ≃L[𝕜] F) :
(p.compContinuousLinearMap u.toContinuousLinearMap).radius ≤ ‖u.symm.toContinuousLinearMap‖ₑ * p.radius :=
by
have :=
(p.compContinuousLinearMap u.toContinuousLinearMap).div_le_radius_compContinuousLinearMap
u.symm.toContinuousLinearMap
simp only [compContinuousLinearMap_comp, ContinuousLinearEquiv.coe_comp_coe_symm, compContinuousLinearMap_id] at this
rwa [ENNReal.div_le_iff' (by simpa [DFunLike.ext_iff] using exists_ne 0) (by simp)] at this