It is probably not the case that Julius is a swan. It is unlikely that Winona is a mouse. It is probably not the case that Fred moved to the office. There is a very good chance that if either 'Fred moved to the office' or 'Julius is a swan' but not both then Brian is yellow. Chances are about even that if 'Winona is a mouse and Fred moved to the office' then Mary took the football. It is impossible that if either 'Fred moved to the office' or 'Julius is a swan' but not both then John dropped the milk.
It is likely that 'Brian is yellow and Winona is a mouse'.
It is highly unlikely that 'Brian is yellow and Winona is a mouse'.
It is likely that 'Brian is yellow and Winona is a mouse'.

  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
  0.25::factA.
  0.2::factB.
  0.25::factC.
  %hop1
  0.8::factX:-xor(factC,factA).
  0.5::factY:-and(factB,factC).
  0.0::factZ:-xor(factC,factA).

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

  query(conclusion).
  
'Brian is yellow and Winona is a mouse'.