There is almost no chance that Mary dropped the apple. We believe that Brian is a lion. It is highly unlikely that Greg is a rhino. We doubt that if either 'Greg is a rhino' or 'Brian is a lion' but not both then Winona is a wolf. It is impossible that if either 'Greg is a rhino' or 'Brian is a lion' but not both then John moved to the garden. There is a better than even chance that if 'Greg is a rhino and Brian is a lion' then Julius is a swan.
It is impossible that 'Julius is a swan and John moved to the garden'.
It is impossible that 'Julius is a swan and John moved to the garden'.
It is probably the case that 'Julius is a swan and John moved to the garden'.

  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.
  0.75::factB.
  0.05::factC.
  %hop1
  0.2::factX:-xor(factC,factB).
  0.0::factY:-xor(factC,factB).
  0.6::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Julius is a swan and John moved to the garden'.