There is almost no chance that John left the apple. Chances are slight that Brian is green. There is little chance that Daniel got the milk. It is highly unlikely that if either 'John left the apple' or 'Brian is green' but not both then Sandra dropped the apple. We believe that if 'Daniel got the milk and John left the apple' then Julius is a lion. There is little chance that if 'Daniel got the milk' or 'John left the apple' or both then Greg is a rhino.
It is almost certain that 'John left the apple and Julius is a lion'.
It is impossible that 'John left the apple and Julius is a lion'.
It is almost certain that 'John left the apple and Julius is a lion'.

  and(A,B) :- A,B.
  or(A,B) :- A;B.
  nand(A,B) :- not(and(A,B)).
  nor(A,B) :- not(or(A,B)).
  xor(A,B) :- or(A,B), nand(A,B).

  %hop0
  0.02::factA.
  0.1::factB.
  0.1::factC.
  %hop1
  0.05::factX:-xor(factA,factB).
  0.75::factY:-and(factC,factA).
  0.1::factZ:-or(factC,factA).

  %hop2
  conclusion:-and(factA,factY).

  query(conclusion).
  
'John left the apple and Julius is a lion'.