added theorem modification git-svn-id: https://svn-agbkb.informatik.uni-bremen.de/Hets/trunk@14098 cec4b9c1-7d33-0410-9eda-942365e851bb
single node tests git-svn-id: https://svn-agbkb.informatik.uni-bremen.de/Hets/trunk@14070 cec4b9c1-7d33-0410-9eda-942365e851bb