Forcings constructed along morasses
  In a previous paper, we introduced a way of constructing a forcing along a simplified gap-1 morass such that the forcing satisfies a chain condition. Now, we generalize this to gap-2 morasses. As an application, we prove that GCH is consistent with the existence of a 0-dimensional Hausdorff topology on $\omega_3$ which has spread $\omega_1$. 
Bernhard Irrgang