Source: wikibot/3-manifolds
= 3-manifolds
{wiki=3-manifolds}
A **3-manifold** is a topological space that locally resembles Euclidean 3-dimensional space \\(\\mathbb\{R\}^3\\). More formally, a 3-manifold is a Hausdorff space that is second-countable (any open cover has a countable subcover), and for every point in the manifold, there exists a neighborhood that is homeomorphic to an open subset of \\(\\mathbb\{R\}^3\\).