Model Solution (3a)

We just updated our model solution in SVN (and added a link to the course schedule), to address an interesting corner case: the default value for array cells is not defined by the Common Lisp standard, unless the :initial-element keyword argument is given to make-array().  Because our code depends on ‘empty’ cells (corresponding to unseen events) to contain nil (the default element in ACL, but apparently not in SBCL), this is an important correction in terms of standard compliance.  At the same time, we have filled in missing comments and generally tried to improve readability of the code; please see for yourselves.

Jakob is working hard to send feedback as fast as possible, and by now has completed reviewing well over half of the submissions we received.