English
For a NormedRing R, the RingNorm obtained from the norm satisfies equality with the standard norm: (NormedRing.toRingNorm R) x = ||x||.
Русский
Для NormedRing R нормированная структура RingNorm даёт равенство: (NormedRing.toRingNorm R) x = ||x||.
LaTeX
$$$(\text{NormedRing.toRingNorm } R)\, x = \|x\|$$$
Lean4
/-- The norm on a `NormedRing`, as a `RingNorm`. -/
@[simps]
def toRingNorm (R : Type*) [NormedRing R] : RingNorm R
where
toFun := norm
map_zero' := norm_zero
add_le' := norm_add_le
mul_le' := norm_mul_le
neg' := norm_neg
eq_zero_of_map_eq_zero' x hx := by rw [← norm_eq_zero]; exact hx