Definition:Homeomorphism/Metric Spaces/Definition 1

Definition
Let $M_1 = \struct {A_1, d_1}$ and $M_2 = \struct {A_2, d_2}$ be metric spaces.

Let $f: A_1 \to A_2$ be a bijection such that:
 * $f$ is continuous from $M_1$ to $M_2$
 * $f^{-1}$ is continuous from $M_2$ to $M_1$.

Then:
 * $f$ is a homeomorphism
 * $M_1$ and $M_2$ are homeomorphic.

Also known as
A homeomorphism is also known as a topological equivalence.

Two homeomorphic metric spaces can be described as topologically equivalent.

Also see

 * Equivalence of Definitions of Homeomorphic Metric Spaces