Jeremias and Luca, The code looks very good. I am impressed how all the details of the stepping algorithm and the Knuth elements have been implemented by you. I am also impressed by the strength of the stepping algorithm. The more I turn it around, the stronger it seems to be.
I found two small points: 1. A penalty for the header and footer is added at the last step; it should be omitted. 2. When a grid unit is incomplete at the page break, it is not rendered on the first page. Regards, Simon -- Simon Pepping home page: http://www.leverkruid.nl