E : Type u_1
inst✝ : SeminormedCommGroup E
ε δ : ℝ
s t : Set E
x y : E
⊢ {x | EMetric.infEdist x s ≤ ENNReal.ofReal δ}⁻¹ = {x | EMetric.infEdist x⁻¹ s ≤ ENNReal.ofReal δ}
E : Type u_1
inst✝ : SeminormedCommGroup E
ε δ : ℝ
s t : Set E
x y : E
⊢ (cthickening δ s)⁻¹ = cthickening δ s⁻¹
simp_rw [cthickening, ← infEdist_inv]
no goals
E : Type u_1
inst✝ : SeminormedCommGroup E
ε δ : ℝ
s t : Set E
x y : E
⊢ {x | EMetric.infEdist x s ≤ ENNReal.ofReal δ}⁻¹ = {x | EMetric.infEdist x⁻¹ s ≤ ENNReal.ofReal δ}
rfl