English
The distance after multiplying by the same y on the right is controlled by the distance in the left factor.
Русский
Расстояние после умножения с одной стороны на одно и то же y контролируется расстоянием между левые множители.
LaTeX
$$dist(x1•y, x2•y) ≤ dist(x1,x2) · dist(y,0)$$
Lean4
instance (priority := 100) toUniformContinuousConstSMul : UniformContinuousConstSMul α β :=
⟨fun c => ((lipschitzWith_iff_dist_le_mul (K := nndist c 0)).2 fun _ _ => dist_smul_pair c _ _).uniformContinuous⟩
-- this instance could be deduced from `NormedSpace.isBoundedSMul`, but we prove it separately
-- here so that it is available earlier in the hierarchy