  This paper discusses ER = EPR, the hypothesis of Susskind and Maldacena that
entangled black holes are connected by an Einstein-Rosen bridge, and that more
generally, quantum entanglement is accompanied by topological connectivity.
Given a background space and a quantum tensor network, we describe how to
construct a new topological space, that welds the network and the background
space together. This construction embodies the principle that quantum
entanglement and topological connectivity are intimately related.
