It is likely that Mary got the apple. It is probable that John is in the garden. There is almost no chance that Winona is a wolf. It is certain that if 'John is in the garden' or 'Winona is a wolf' or both then Bernhard is gray. It is probably the case that if either 'Mary got the apple' or 'John is in the garden' but not both then Julius is white. We believe that if 'Winona is a wolf and Mary got the apple' then Sandra left the football.
It is likely that 'Bernhard is gray and John is in the garden'.
It is likely that 'Bernhard is gray and John is in the garden'.
Chances are slight that 'Bernhard is gray and John is in the garden'.

  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.
  0.7::factB.
  0.02::factC.
  %hop1
  1.0::factX:-or(factB,factC).
  0.7::factY:-xor(factA,factB).
  0.75::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Bernhard is gray and John is in the garden'.