We believe that Julius is a swan. It is probably not the case that John went to the garden. We believe that Greg is a rhino. We doubt that if either 'John went to the garden' or 'Julius is a swan' but not both then Winona is a wolf. It is almost certain that if either 'John went to the garden' or 'Greg is a rhino' but not both then Mary left the milk. It is highly unlikely that if 'John went to the garden' or 'Greg is a rhino' or both then Gertrude is a sheep.
It is certain that 'Gertrude is a sheep and Mary left the milk'.
There is almost no chance that 'Gertrude is a sheep and Mary left the milk'.
It is certain that 'Gertrude is a sheep and Mary left the milk'.

  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
  0.75::factA.
  0.25::factB.
  0.75::factC.
  %hop1
  0.2::factX:-xor(factB,factA).
  0.95::factY:-xor(factB,factC).
  0.05::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Gertrude is a sheep and Mary left the milk'.