What has changed wrt the original:

Generally the new headerfiles are now working.

fourfivesix.tex: 
Theorem 6.16   slightly modified (wrong before)
Theorem 7.6(2) slightly modified (wrong before)

proofappendix.tex:
Proof of Theorem 6.16   slightly modified
Proof of Theorem 7.6    slightly modified

secondproofappendix.tex:
Proof of Theorem 9.12   B replaced with A (wrong before)

basic.tex:
\uplus now on classes.
Example 2.1: comma removed.
order-sorted made more beautiful.

motivation.tex:
Many suble changes from Chapter "The importance of confluence" on.