It is almost certain that Daniel took the milk. Chances are slight that Brian is a rhino. There is little chance that Greg is gray. It is highly likely that if 'Daniel took the milk and Brian is a rhino' then Lily is a swan. It is highly likely that if 'Daniel took the milk and Brian is a rhino' then John went to the hallway. We doubt that if 'Brian is a rhino' or 'Greg is gray' or both then Fred left the apple.
Chances are slight that 'Brian is a rhino' or 'Fred left the apple' or both.
Chances are slight that 'Brian is a rhino' or 'Fred left the apple' or both.
It is likely that 'Brian is a rhino' or 'Fred left the apple' or both.

  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
  0.95::factA.
  0.1::factB.
  0.1::factC.
  %hop1
  0.9::factX:-and(factA,factB).
  0.9::factY:-and(factA,factB).
  0.2::factZ:-or(factB,factC).

  %hop2
  conclusion:-or(factB,factZ).

  query(conclusion).
  
'Brian is a rhino' or 'Fred left the apple' or both.