It is almost certain that Bernhard is gray. There is a very good chance that Greg is yellow. It is probably the case that Lily is a lion. It is probable that if either 'Bernhard is gray' or 'Lily is a lion' but not both then Emily is a sheep. It is highly unlikely that if either 'Bernhard is gray' or 'Lily is a lion' but not both then Julius is a swan. There is a better than even chance that if 'Lily is a lion' or 'Bernhard is gray' or both then Mary got the apple.
There is a very good chance that 'Greg is yellow' or 'Julius is a swan' or both.
There is a very good chance that 'Greg is yellow' or 'Julius is a swan' or both.
There is little chance that 'Greg is yellow' or 'Julius is a swan' 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.
  0.8::factB.
  0.7::factC.
  %hop1
  0.7::factX:-xor(factA,factC).
  0.05::factY:-xor(factA,factC).
  0.6::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Greg is yellow' or 'Julius is a swan' or both.