diff --git a/Mathlib/Topology/UniformSpace/Compact.lean b/Mathlib/Topology/UniformSpace/Compact.lean index 97c5a9266ef0d..364e8b1bbad26 100644 --- a/Mathlib/Topology/UniformSpace/Compact.lean +++ b/Mathlib/Topology/UniformSpace/Compact.lean @@ -169,9 +169,10 @@ def uniformSpaceOfCompactT2 [TopologicalSpace γ] [CompactSpace γ] [T2Space γ] continuous. -/ theorem CompactSpace.uniformContinuous_of_continuous [CompactSpace α] {f : α → β} (h : Continuous f) : UniformContinuous f := - have : Tendsto (Prod.map f f) (𝓝ˢ (diagonal α)) (𝓝ˢ (diagonal β)) := - (h.prod_map h).tendsto_nhdsSet mapsTo_prod_map_diagonal - (this.mono_left nhdsSet_diagonal_eq_uniformity.ge).mono_right nhdsSet_diagonal_le_uniformity +calc map (Prod.map f f) (𝓤 α) + = map (Prod.map f f) (𝓝ˢ (diagonal α)) := by rw [nhdsSet_diagonal_eq_uniformity] + _ ≤ 𝓝ˢ (diagonal β) := (h.prod_map h).tendsto_nhdsSet mapsTo_prod_map_diagonal + _ ≤ 𝓤 β := nhdsSet_diagonal_le_uniformity #align compact_space.uniform_continuous_of_continuous CompactSpace.uniformContinuous_of_continuous /-- Heine-Cantor: a continuous function on a compact set of a uniform space is uniformly