Problem set 3 marking scheme.  Out of 40.

1) swap - parameter passing     14
   a) by value                     2
   b) by value-result              4
   c) by reference                 4
   d) by name                      4

2) Scoping rules                11
   a) static                       8
   b) dynamic                      3

3) Stack trace                  15
   a) using access links           10
   b) using a display              5