Knot and link projections in 3-manifolds (Q910054)

The Reidemeister Theorem says that two links in the 3-sphere are combinatorially equivalent if and only if the projection of one link can be deformed by certain operations to a projection of the other link. The operations are known as Reidemeister Operations. In this paper we define the notion of a link projection in an arbitrary closed 3-manifold and we prove a generalization of the above theorem.