It is impossible that Brian is green. It is highly likely that Greg is gray. It is almost certain that Lily is a lion. There is little chance that if 'Greg is gray' or 'Brian is green' or both then Winona is a mouse. It is probably the case that if either 'Lily is a lion' or 'Brian is green' but not both then Jeff left the apple. It is probable that if either 'Brian is green' or 'Lily is a lion' but not both then Bernhard is a frog.
It is improbable that either 'Brian is green' or 'Lily is a lion' but not both.
It is almost certain that either 'Brian is green' or 'Lily is a lion' but not both.
It is improbable that either 'Brian is green' or 'Lily is a lion' but not 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
  0.0::factA.
  0.9::factB.
  0.95::factC.
  %hop1
  0.1::factX:-or(factB,factA).
  0.7::factY:-xor(factC,factA).
  0.7::factZ:-xor(factA,factC).

  %hop2
  conclusion:-xor(factA,factC).

  query(conclusion).
  
Either 'Brian is green' or 'Lily is a lion' but not both.