There is a better than even chance that John discarded the milk. It is likely that Lily is a swan. We doubt that Julius is a rhino. It is likely that if either 'Lily is a swan' or 'John discarded the milk' but not both then Mary dropped the apple. There is a very good chance that if 'John discarded the milk and Lily is a swan' then Jessica is a mouse. It is probable that if 'John discarded the milk' or 'Lily is a swan' or both then Bernhard is yellow.
It is certain that 'Jessica is a mouse' or 'Julius is a rhino' or both.
Chances are about even that 'Jessica is a mouse' or 'Julius is a rhino' or both.
It is certain that 'Jessica is a mouse' or 'Julius is a rhino' 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
  0.6::factA.
  0.7::factB.
  0.2::factC.
  %hop1
  0.7::factX:-xor(factB,factA).
  0.8::factY:-and(factA,factB).
  0.7::factZ:-or(factA,factB).

  %hop2
  conclusion:-or(factY,factC).

  query(conclusion).
  
'Jessica is a mouse' or 'Julius is a rhino' or both.