It is probable that Mary grabbed the apple. It is impossible that Lily is a swan. It is unlikely that Greg is a lion. It is unlikely that if either 'Greg is a lion' or 'Lily is a swan' but not both then Winona is a cat. It is highly unlikely that if 'Lily is a swan and Greg is a lion' then Bill went to the garden. It is likely that if either 'Mary grabbed the apple' or 'Lily is a swan' but not both then Brian is green.
It is almost certain that 'Brian is green' or 'Winona is a cat' or both.
Chances are about even that 'Brian is green' or 'Winona is a cat' or both.
It is almost certain that 'Brian is green' or 'Winona 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
  0.7::factA.
  0.0::factB.
  0.2::factC.
  %hop1
  0.2::factX:-xor(factC,factB).
  0.05::factY:-and(factB,factC).
  0.7::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Brian is green' or 'Winona is a cat' or both.