Comment by rramadass

This is called the Closed World Assumption (CWA) - https://en.wikipedia.org/wiki/Closed-world_assumption

Prolog’s Closed-World Assumption: A Journey Through Time - https://medium.com/@kenichisasagawa/prologs-closed-world-ass...

Is Prolog really based on the closed-world assumption? - https://stackoverflow.com/questions/65014705/is-prolog-reall...