English
Two intermediate fields are linearly disjoint iff their substituted subtype ranges are linearly disjoint.
Русский
Два промежуточных поля линейно неразделимы тогда и только тогда, когда их подстановочные диапазоны совместно линейно неразделимы.
LaTeX
$$$A.LinearDisjoint B \\iff A.toSubalgebra.LinearDisjoint B.toSubalgebra$ .$$
Lean4
/-- Two intermediate fields are linearly disjoint if and only if
they are linearly disjoint as subalgebras. -/
theorem linearDisjoint_iff' : A.LinearDisjoint B ↔ A.toSubalgebra.LinearDisjoint B.toSubalgebra :=
by
rw [linearDisjoint_iff]
congr!
ext; simp