It is probably the case that Julius is a swan. We doubt that Fred moved to the office. There is a better than even chance that Bernhard is yellow. Chances are about even that if 'Fred moved to the office' or 'Bernhard is yellow' or both then Greg is a rhino. It is probable that if 'Julius is a swan and Fred moved to the office' then John put down the milk. Chances are slight that if 'Fred moved to the office' or 'Bernhard is yellow' or both then Brian is a swan.
It is highly unlikely that 'Bernhard is yellow and John put down the milk'.
It is highly unlikely that 'Bernhard is yellow and John put down the milk'.
It is likely that 'Bernhard is yellow and John put down 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
  0.7::factA.
  0.2::factB.
  0.6::factC.
  %hop1
  0.5::factX:-or(factB,factC).
  0.7::factY:-and(factA,factB).
  0.1::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Bernhard is yellow and John put down the milk'.