There is almost no chance that John went to the garden. It is probably the case that Sandra got the football. It is almost certain that Brian is a swan. It is unlikely that if 'Sandra got the football and John went to the garden' then Julius is a lion. It is unlikely that if 'Sandra got the football' or 'John went to the garden' or both then Greg is a frog. There is a very good chance that if 'Sandra got the football' or 'Brian is a swan' or both then Fred dropped the milk.
It is impossible that 'Fred dropped the milk and Sandra got the football'.
There is a better than even chance that 'Fred dropped the milk and Sandra got the football'.
It is impossible that 'Fred dropped the milk and Sandra got the football'.

  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
  0.02::factA.
  0.7::factB.
  0.95::factC.
  %hop1
  0.2::factX:-and(factB,factA).
  0.2::factY:-or(factB,factA).
  0.8::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Fred dropped the milk and Sandra got the football'.