English
In a metric space M where M acts on itself by left multiplication by a, the distance satisfies dist(a b, a c) = dist(b, c) for all a,b,c ∈ M.
Русский
В метрическом пространстве M, где M действует на себе по левому умножению на a, выполняется dist(a b, a c) = dist(b, c) для всех a,b,c ∈ M.
LaTeX
$$$\operatorname{dist}(a b, a c) = \operatorname{dist}(b, c)$$$
Lean4
@[to_additive (attr := simp)]
theorem dist_mul_left [PseudoMetricSpace M] [Mul M] [IsIsometricSMul M M] (a b c : M) :
dist (a * b) (a * c) = dist b c :=
dist_smul a b c