Chances are about even that Mary dropped the apple. It is improbable that Winona is a wolf. It is highly unlikely that Brian is yellow. It is almost certain that if 'Brian is yellow' or 'Mary dropped the apple' or both then Julius is a swan. It is probably the case that if either 'Winona is a wolf' or 'Mary dropped the apple' but not both then John left the football. It is likely that if 'Winona is a wolf and Mary dropped the apple' then Sandra took the milk.
It is highly unlikely that 'Sandra took the milk and Winona is a wolf'.
It is highly unlikely that 'Sandra took the milk and Winona is a wolf'.
It is probably the case that 'Sandra took the milk and Winona is a wolf'.

  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
  0.5::factA.
  0.1::factB.
  0.05::factC.
  %hop1
  0.95::factX:-or(factC,factA).
  0.7::factY:-xor(factB,factA).
  0.7::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Sandra took the milk and Winona is a wolf'.