It is improbable that Bill moved to the office. It is unlikely that Greg is a rhino. It is likely that Daniel took the milk. There is a better than even chance that if 'Greg is a rhino and Bill moved to the office' then Sandra left the milk. It is almost certain that if 'Daniel took the milk and Bill moved to the office' then Brian is a frog. Chances are slight that if 'Daniel took the milk and Bill moved to the office' then Bernhard is a swan.
We believe that 'Brian is a frog and Daniel took the milk'.
It is highly unlikely that 'Brian is a frog and Daniel took the milk'.
We believe that 'Brian is a frog and Daniel took 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
  0.1::factA.
  0.2::factB.
  0.7::factC.
  %hop1
  0.6::factX:-and(factB,factA).
  0.95::factY:-and(factC,factA).
  0.1::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Brian is a frog and Daniel took the milk'.