It is highly unlikely that John discarded the milk. There is a better than even chance that Fred is in the cinema. It is probably not the case that Julius is gray. Chances are about even that if 'Fred is in the cinema and Julius is gray' then Mary put down the milk. It is improbable that if 'Julius is gray and Fred is in the cinema' then Bernhard is white. It is probably the case that if either 'John discarded the milk' or 'Julius is gray' but not both then Lily is a swan.
It is likely that 'John discarded the milk and Lily is a swan'.
There is almost no chance that 'John discarded the milk and Lily is a swan'.
It is likely that 'John discarded the milk and Lily is a swan'.

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

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

  query(conclusion).
  
'John discarded the milk and Lily is a swan'.