experiments with incremental solving
further experiments
finish work on incremental solving (except minimality check)
start implementing incremental UFS checks
implementation of UFS checker for incrementally extended programs
extensions in AnnotatedGroundProgram
extensions in AnnotatedGroundProgram
some updates
add a comment
add some debug outputs
fix a bug
upgrade to clasp 3.1.1
work on incremental solving
fix a bug in UFS checker
fixes in incremental solving algorithm