It is highly likely that Julius is gray. There is a better than even chance that Greg is a rhino. It is almost certain that Brian is a frog. It is probably not the case that if 'Julius is gray' or 'Greg is a rhino' or both then Fred put down the apple. It is unlikely that if 'Greg is a rhino and Brian is a frog' then Lily is yellow. There is a very good chance that if either 'Julius is gray' or 'Greg is a rhino' but not both then Mary picked up the milk.
It is highly likely that 'Fred put down the apple' or 'Julius is gray' or both.
It is highly likely that 'Fred put down the apple' or 'Julius is gray' or both.
It is unlikely that 'Fred put down the apple' or 'Julius is gray' 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
  0.9::factA.
  0.6::factB.
  0.95::factC.
  %hop1
  0.25::factX:-or(factA,factB).
  0.2::factY:-and(factB,factC).
  0.8::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Fred put down the apple' or 'Julius is gray' or both.