It is probably not the case that Julius is a lion. It is almost certain that Greg is white. There is little chance that Brian is a rhino. It is probably not the case that if 'Greg is white' or 'Brian is a rhino' or both then Daniel got the football. It is likely that if either 'Brian is a rhino' or 'Julius is a lion' but not both then Jessica is a cat. It is highly likely that if 'Brian is a rhino' or 'Greg is white' or both then Mary grabbed the milk.
It is likely that either 'Mary grabbed the milk' or 'Jessica is a cat' but not both.
It is likely that either 'Mary grabbed the milk' or 'Jessica is a cat' but not both.
We doubt that either 'Mary grabbed the milk' or 'Jessica is a cat' 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
  0.25::factA.
  0.95::factB.
  0.1::factC.
  %hop1
  0.25::factX:-or(factB,factC).
  0.7::factY:-xor(factC,factA).
  0.9::factZ:-or(factC,factB).

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

  query(conclusion).
  
Either 'Mary grabbed the milk' or 'Jessica is a cat' but not both.