added formulas from page 10+11 of overview git-svn-id: https://svn-agbkb.informatik.uni-bremen.de/Hets/trunk@10506 cec4b9c1-7d33-0410-9eda-942365e851bb
test cases from the overview git-svn-id: https://svn-agbkb.informatik.uni-bremen.de/Hets/trunk@8066 cec4b9c1-7d33-0410-9eda-942365e851bb