English
The Jacobson radical of the radical of an ideal I equals the Jacobson radical of I itself: I.radical.jacobson = I.jacobson.
Русский
Радикал Якобсона радикала идеала I равен радикалу Якобсона самого I: I.radical.jacobson = I.jacobson.
LaTeX
$$$I.\mathrm{radical}.\mathrm{jacobson} = I.\mathrm{jacobson}$$$
Lean4
theorem jacobson_radical_eq_jacobson : I.radical.jacobson = I.jacobson :=
le_antisymm
(le_trans (le_of_eq (congr_arg jacobson (radical_eq_sInf I)))
(sInf_le_sInf fun _ hJ => ⟨sInf_le ⟨hJ.1, hJ.2.isPrime⟩, hJ.2⟩))
(jacobson_mono le_radical)