Bugfix: unsafe variables with no positive goals.
selecting values from a recursive relation but no selecting all the f…
Merge branch 'master' of https://github.com/DreamTeamADB/Code
Merge remote-tracking branch 'origin/grigory'
Merge branch 'master' into jaume
Bugfix: Aggregate functions
help added for aggregate functions
Bugfix: Meaning of the universe
Aggregation with anonymous variables bugfix
Simplified not expressions
Recursion with different relations solved
Boolean has_Length and _divides