Suppose we have a KB with the following rules, use forward chaining or backward chaining to show S11 is true, i.e. when 7B00 and 7B10, the space 11 is not a trap and it is safe. "7" means "Not".
KB:
7B00, 7B10, 7B00-->7T10^7T01, 7T10-->S10, 7B10^S10-->7T11, 7T11-->S11.
Query: S11?