The fully off-shell T matrix is generated from a real symmetric function σ(k,k′) which in turn can be obtained from a knowledge of the two-body wave function in the interaction interior. The resulting T matrices are employed to compute the binding energies of 16O, 40Ca, and nuclear matter. Limiting the two-body wave function to physically acceptable forms limits the allowed σ functions. A 'difference integral' is defined in terms of the two-body scattering wave function, which seems to be strongly correlated with the binding energies.