/- Copyright (c) 2021 María Inés de Frutos-Fernández. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: María Inés de Frutos-Fernández -/ import ring_theory.localization.basic import topology.algebra.ring /-! # Localization of topological rings The topological localization of a topological commutative ring `R` at a submonoid `M` is the ring `localization M` endowed with the final ring topology of the natural homomorphism sending `x : R` to the equivalence class of `(x, 1)` in the localization of `R` at a `M`. ## Main Results - `localization.topological_ring`: The localization of a topological commutative ring at a submonoid is a topological ring. -/ variables {R : Type*} [comm_ring R] [topological_space R] {M : submonoid R} /-- The ring topology on `localization M` coinduced from the natural homomorphism sending `x : R` to the equivalence class of `(x, 1)`. -/ def localization.ring_topology : ring_topology (localization M) := ring_topology.coinduced (localization.monoid_of M).to_fun instance : topological_space (localization M) := localization.ring_topology.to_topological_space instance : topological_ring (localization M) := localization.ring_topology.to_topological_ring