It is probably the case that Mary moved to the office. There is almost no chance that John dropped the apple. It is unlikely that Bernhard is a lion. It is almost certain that if either 'John dropped the apple' or 'Bernhard is a lion' but not both then Sandra is in the kitchen. There is little chance that if 'John dropped the apple' or 'Mary moved to the office' or both then Julius is a swan. It is almost certain that if 'Mary moved to the office and John dropped the apple' then Jeff left the apple.
There is almost no chance that 'Julius is a swan and Bernhard is a lion'.
There is almost no chance that 'Julius is a swan and Bernhard is a lion'.
It is almost certain that 'Julius is a swan and Bernhard is a lion'.

  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
  0.7::factA.
  0.02::factB.
  0.2::factC.
  %hop1
  0.95::factX:-xor(factB,factC).
  0.1::factY:-or(factB,factA).
  0.95::factZ:-and(factA,factB).

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

  query(conclusion).
  
'Julius is a swan and Bernhard is a lion'.