It is highly unlikely that Julius is green. It is highly likely that Lily is a lion. Chances are slight that Greg is a lion. It is almost certain that if 'Julius is green' or 'Lily is a lion' or both then Brian is a rhino. There is little chance that if 'Greg is a lion' or 'Julius is green' or both then John dropped the apple. It is highly likely that if either 'Greg is a lion' or 'Julius is green' but not both then Mary left the milk.
It is highly likely that 'Brian is a rhino' or 'John dropped the apple' or both.
It is highly likely that 'Brian is a rhino' or 'John dropped the apple' or both.
There is almost no chance that 'Brian is a rhino' or 'John dropped 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
  0.05::factA.
  0.9::factB.
  0.1::factC.
  %hop1
  0.95::factX:-or(factA,factB).
  0.1::factY:-or(factC,factA).
  0.9::factZ:-xor(factC,factA).

  %hop2
  conclusion:-or(factX,factY).

  query(conclusion).
  
'Brian is a rhino' or 'John dropped the apple' or both.