English
The polar bilinear form is compatible with base change: polarBilin(baseChange Q) = baseChange(polarBilin(Q)).
Русский
Полярная билинейная форма совместима с базовым изменением: polarBilin(baseChange(Q)) = baseChange(polarBilin(Q)).
LaTeX
$$$\\text{polarBilin}(\\text{baseChange } A\, Q) = \\text{BilinForm.baseChange } A (\\text{polarBilin}(Q))$$$
Lean4
/-- The base change of a quadratic form. -/
protected def baseChange (Q : QuadraticForm R M₂) : QuadraticForm A (A ⊗[R] M₂) :=
QuadraticForm.tmul (R := R) (A := A) (M₁ := A) (M₂ := M₂) (QuadraticMap.sq (R := A)) Q