
Introduction to Profinite Groups - MAT-UnB
... View each Gi as a topological space via the discrete topology. Q Let C = i∈I Gi have the product topology. Tychonoff’s Theorem ⇒ C is compact. Easy to see C is Hausdorff. lim Gi = { (gi ) | gi φij = gj ∀i > j } is closed in C. ...
... View each Gi as a topological space via the discrete topology. Q Let C = i∈I Gi have the product topology. Tychonoff’s Theorem ⇒ C is compact. Easy to see C is Hausdorff. lim Gi = { (gi ) | gi φij = gj ∀i > j } is closed in C. ...
LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
... iv) Let X and Y be metric spaces and f be a mapping of X into Y. Then prove that f is continuous iff f 1 (G) is open in X whenever G is open in Y. v) Prove that the set C(X,R) of all bounded continuous real functions defined on a metric space X is a Banech space with respect to point wise addition ...
... iv) Let X and Y be metric spaces and f be a mapping of X into Y. Then prove that f is continuous iff f 1 (G) is open in X whenever G is open in Y. v) Prove that the set C(X,R) of all bounded continuous real functions defined on a metric space X is a Banech space with respect to point wise addition ...
General topology
In mathematics, general topology is the branch of topology that deals with the basic set-theoretic definitions and constructions used in topology. It is the foundation of most other branches of topology, including differential topology, geometric topology, and algebraic topology. Another name for general topology is point-set topology.The fundamental concepts in point-set topology are continuity, compactness, and connectedness: Continuous functions, intuitively, take nearby points to nearby points. Compact sets are those that can be covered by finitely many sets of arbitrarily small size. Connected sets are sets that cannot be divided into two pieces that are far apart. The words 'nearby', 'arbitrarily small', and 'far apart' can all be made precise by using open sets, as described below. If we change the definition of 'open set', we change what continuous functions, compact sets, and connected sets are. Each choice of definition for 'open set' is called a topology. A set with a topology is called a topological space.Metric spaces are an important class of topological spaces where distances can be assigned a number called a metric. Having a metric simplifies many proofs, and many of the most common topological spaces are metric spaces.