It is probably the case that Bernhard is a rhino. We doubt that Fred is in the school. It is almost certain that Sandra dropped the apple. It is probably the case that if 'Sandra dropped the apple' or 'Bernhard is a rhino' or both then Julius is a swan. There is a better than even chance that if 'Sandra dropped the apple and Fred is in the school' then Brian is a frog. It is impossible that if 'Bernhard is a rhino and Fred is in the school' then Greg is a lion.
It is impossible that 'Julius is a swan and Sandra dropped the apple'.
It is probably the case that 'Julius is a swan and Sandra dropped the apple'.
It is impossible that 'Julius is a swan and Sandra dropped the apple'.

  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.
  0.2::factB.
  0.95::factC.
  %hop1
  0.7::factX:-or(factC,factA).
  0.6::factY:-and(factC,factB).
  0.0::factZ:-and(factA,factB).

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

  query(conclusion).
  
'Julius is a swan and Sandra dropped the apple'.