English
A tensor product of symmetric bilinear maps remains symmetric: B1.tmul B2 is symmetric in its two arguments if B1 and B2 are symmetric.
Русский
Тензорное произведение симметричных билинейных форм сохраняет симметрию: B1.tmul B2 симметрично по аргументах, если B1 и B2 симметричны.
LaTeX
$$$\\forall x,y,\\ B_1.\\tmul B_2\\ x\\ y = B_1.\\tmul B_2\\ y\\ x$$$
Lean4
/-- The base change of a bilinear map (also known as "extension of scalars"). -/
protected def baseChange (B : BilinMap R M₂ N₂) : BilinMap A (A ⊗[R] M₂) (A ⊗[R] N₂) :=
BilinMap.tmul (R := R) (A := A) (M₁ := A) (M₂ := M₂) (LinearMap.mul A A) B