There is a better than even chance that Mary picked up the milk. It is probable that Jessica is a mouse. Chances are slight that Greg is a lion. We believe that if 'Mary picked up the milk' or 'Jessica is a mouse' or both then Brian is green. It is almost certain that if 'Greg is a lion' or 'Jessica is a mouse' or both then Winona is a wolf. It is certain that if 'Greg is a lion and Mary picked up the milk' then Lily is white.
It is impossible that 'Jessica is a mouse' or 'Lily is white' or both.
It is likely that 'Jessica is a mouse' or 'Lily is white' or both.
It is impossible that 'Jessica is a mouse' or 'Lily is white' 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.
  0.1::factC.
  %hop1
  0.75::factX:-or(factA,factB).
  0.95::factY:-or(factC,factB).
  1.0::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Jessica is a mouse' or 'Lily is white' or both.