Journal of Statistical Physics, Vol. 50, Nos. 5/6, 1988. p. 1179-1200.
A study is made of the statistical mechanics of classical lattice spin systems with finite-range interactions in two dimensions. By means of a decimation procedure, a finite-size condition is given for the convergence of a cluster expansion that is believed to be useful for treating the range of temperature between the critical one Tc and the estimated threshold To of convergence of the usual high-temperature expansion.