It is certain that Sandra took the football. Chances are slight that Gertrude is a cat. It is unlikely that Daniel got the milk. It is almost certain that if 'Daniel got the milk and Gertrude is a cat' then Winona is a wolf. It is highly unlikely that if 'Daniel got the milk and Gertrude is a cat' then Jessica is a mouse. Chances are slight that if 'Gertrude is a cat' or 'Daniel got the milk' or both then Julius is gray.
It is certain that 'Sandra took the football' or 'Gertrude is a cat' or both.
It is certain that 'Sandra took the football' or 'Gertrude is a cat' or both.
It is highly unlikely that 'Sandra took the football' 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
  1.0::factA.
  0.1::factB.
  0.2::factC.
  %hop1
  0.95::factX:-and(factC,factB).
  0.05::factY:-and(factC,factB).
  0.1::factZ:-or(factB,factC).

  %hop2
  conclusion:-or(factA,factB).

  query(conclusion).
  
'Sandra took the football' or 'Gertrude is a cat' or both.