English
Copy of a NonUnitalSubalgebra S with carrier s = ↑S yields a nonunital subalgebra with the same structure.
Русский
Копия ненулевой подпалгебры S с карриером s = ↑S сохраняет ту же структуру.
LaTeX
$$$\text{copy}(S, s, hs) = S$$$
Lean4
/-- Copy of a non-unital subalgebra with a new `carrier` equal to the old one.
Useful to fix definitional equalities. -/
protected def copy (S : NonUnitalSubalgebra R A) (s : Set A) (hs : s = ↑S) : NonUnitalSubalgebra R A :=
{ S.toNonUnitalSubsemiring.copy s hs with smul_mem' r a := by simpa [hs] using S.smul_mem r }