We doubt that Greg is gray. It is unlikely that Brian is yellow. It is almost certain that Julius is a rhino. It is probably the case that if either 'Brian is yellow' or 'Julius is a rhino' but not both then Mary left the apple. There is a very good chance that if either 'Brian is yellow' or 'Greg is gray' but not both then Lily is a lion. It is highly unlikely that if 'Brian is yellow and Greg is gray' then Daniel got the milk.
It is probably not the case that 'Brian is yellow' or 'Lily is a lion' or both.
It is probably not the case that 'Brian is yellow' or 'Lily is a lion' or both.
It is probably the case that 'Brian is yellow' or 'Lily is a lion' 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
  0.2::factA.
  0.2::factB.
  0.95::factC.
  %hop1
  0.7::factX:-xor(factB,factC).
  0.8::factY:-xor(factB,factA).
  0.05::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Brian is yellow' or 'Lily is a lion' or both.