English
The radical distributes over addition: radical(I ⊔ J) = radical(radical(I) ⊔ radical(J)).
Русский
Радикал распространяется на сумму: √(I + J) = √(√I + √J).
LaTeX
$$$\\operatorname{radical}(I \\lor J) = \\operatorname{radical}(\\operatorname{radical}(I) \\lor \\operatorname{radical}(J))$$$
Lean4
theorem radical_sup : radical (I ⊔ J) = radical (radical I ⊔ radical J) :=
le_antisymm (radical_mono <| sup_le_sup le_radical le_radical) <|
radical_le_radical_iff.2 <| sup_le (radical_mono le_sup_left) (radical_mono le_sup_right)