Very cool!
Could you elaborate on what it means that DatalogF3 is a ‘PER’?
The above still doesn’t fully explain what it is. Since if it is not TRUE, what is it then? Well the answer is, since SQL has 3-valued logic, it is UNKNOWN and not FALSE.
= NULL 0 1
NULL UNKNOWN UNKNOWN UNKNOWN
0 UNKNOWN TRUE FALSE
1 UNKNOWN FALSE TRUE
Edit 01.03.2021:
Dont forget to like and share DatalogF3 on Twitter. Yesterday I encountered a PhD student in Logic from Vienna. He didn’t know Free Logic. So these institutions could improve!