Using the already-established results Dmax(chain A) = 19.5698 angstrom, Dmax(chain B) = 19.2646 angstrom, and Dmax(dimer) = 28.7192 angstrom, compute the sum of the two individual monomer extents and compare it to the dimer's own extent. Report the sum and the signed difference (sum minus dimer extent) in angstrom to four decimal places. Is the dimer's extent close to, less than, or greater than the sum of the two monomer extents, and what does this imply about how the two monomers are arranged relative to each other (e.g. extending end-to-end versus overlapping side-by-side)?

This is a reasoning task over the already-computed Dmax values from the preceding three questions; no new coordinate file or calculation beyond simple arithmetic and geometric reasoning is required.