Combination Theorem for Continuous Mappings/Topological Ring/Translation Rule

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Theorem

Let $\struct{S, \tau_{_S}}$ be a topological space.

Let $\struct{R, +, *, \tau_{_R}}$ be a topological ring.


Let $\lambda \in R$.

Let $f: \struct{S, \tau_{_S}} \to \struct{R, \tau_{_R}}$ be a continuous mapping.


Let $\lambda + f : S \to R$ be the mapping defined by:

$\forall x \in S: \map {\paren{\lambda + f}} x = \lambda + \map f x$


Then

$\lambda + f : \struct{S, \tau_{_S}} \to \struct{R, \tau_{_R}}$ is continuous.


Proof

By definition of a topological ring, $\struct{R, +, \tau_{_R}}$ is a topological group.

From Multiple Rule for Continuous Mappings to Topological Group, $\lambda + f : \struct{S, \tau_{_S}} \to \struct{R, \tau_{_R}}$ is a continuous mapping.

$\blacksquare$

Also see