In topology, puncturing a manifold is removing a finite set of points from that manifold.
In this case, the manifold is known as once-punctured.
With the removal of a second point, it becomes twice-punctured, and so on.
Examples of punctured manifolds include the open disk (which is a sphere with a single puncture), the cylinder (which is a sphere with two punctures),[1] and the Möbius strip (which is a projective plane with a single puncture).
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