“…The point of using this loop-cluster definition for the importance sampling of classical spin systems, as was treated rigorously in [17] [18], is that the sum over discrete steps in the probabilistic Markov chain, M, can then essentially be interchanged with the sum over discrete loop-clusters in the definition of the lattice partition function, which leads to more efficient numerical sampling. As was noticed in [15] and [16], however, when this loop-cluster definition of the new lattice configurations is applied to the Trotter-Suzuki formalism in (4), this definition has the advantage that closed loops on the D +1 dimensional lattice in (4) automatically preserve the definition of the trace. Therefore, as is used explicitly in [15], using this approach it is possible to interchange, t, with, M, and to define the lattice partition via the with respect to a trace operation defined over the length of the Markov chain, rather than with respect to Euclidean-time.…”