It is highly unlikely that Julius is gray. It is probable that Brian is a lion. It is certain that Winona is a mouse. We believe that if 'Brian is a lion' or 'Winona is a mouse' or both then Sandra left the milk. There is little chance that if 'Brian is a lion' or 'Winona is a mouse' or both then Emily is a sheep. It is probably not the case that if 'Julius is gray and Winona is a mouse' then John put down the apple.
It is improbable that either 'Emily is a sheep' or 'Julius is gray' but not both.
It is improbable that either 'Emily is a sheep' or 'Julius is gray' but not both.
There is a better than even chance that either 'Emily is a sheep' or 'Julius is gray' 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
  0.05::factA.
  0.7::factB.
  1.0::factC.
  %hop1
  0.75::factX:-or(factB,factC).
  0.1::factY:-or(factB,factC).
  0.25::factZ:-and(factA,factC).

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

  query(conclusion).
  
Either 'Emily is a sheep' or 'Julius is gray' but not both.