There is almost no chance that Greg is a rhino. It is probable that Mary got the football. It is probably not the case that Daniel left the milk. There is little chance that if either 'Greg is a rhino' or 'Daniel left the milk' but not both then Brian is white. It is probably the case that if either 'Mary got the football' or 'Daniel left the milk' but not both then Julius is gray. Chances are slight that if 'Greg is a rhino and Daniel left the milk' then Emily is a mouse.
There is a better than even chance that either 'Julius is gray' or 'Daniel left the milk' but not both.
There is a better than even chance that either 'Julius is gray' or 'Daniel left the milk' but not both.
There is almost no chance that either 'Julius is gray' or 'Daniel left the milk' 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
  0.02::factA.
  0.7::factB.
  0.25::factC.
  %hop1
  0.1::factX:-xor(factA,factC).
  0.7::factY:-xor(factB,factC).
  0.1::factZ:-and(factA,factC).

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

  query(conclusion).
  
Either 'Julius is gray' or 'Daniel left the milk' but not both.