It is unlikely that Daniel took the football. Chances are slight that Julius is a swan. It is improbable that Bernhard is yellow. It is probable that if either 'Daniel took the football' or 'Bernhard is yellow' but not both then Gertrude is a cat. It is probably the case that if 'Julius is a swan' or 'Daniel took the football' or both then John went to the garden. There is a better than even chance that if 'Daniel took the football and Julius is a swan' then Winona is a mouse.
It is certain that 'John went to the garden' or 'Gertrude is a cat' or both.
It is probably not the case that 'John went to the garden' or 'Gertrude is a cat' or both.
It is certain that 'John went to the garden' or 'Gertrude is a cat' or both.

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

  %hop2
  conclusion:-or(factY,factX).

  query(conclusion).
  
'John went to the garden' or 'Gertrude is a cat' or both.