It is highly unlikely that Julius is white. It is probably not the case that Jeff went to the bedroom. We doubt that Lily is a lion. There is a better than even chance that if 'Julius is white and Jeff went to the bedroom' then Jessica is a mouse. It is likely that if either 'Julius is white' or 'Lily is a lion' but not both then Sumit is thirsty. Chances are slight that if 'Julius is white' or 'Lily is a lion' or both then Greg is a frog.
It is certain that either 'Greg is a frog' or 'Jessica is a mouse' but not both.
There is almost no chance that either 'Greg is a frog' or 'Jessica is a mouse' but not both.
It is certain that either 'Greg is a frog' or 'Jessica is a mouse' but not 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
  0.05::factA.
  0.25::factB.
  0.2::factC.
  %hop1
  0.6::factX:-and(factA,factB).
  0.7::factY:-xor(factA,factC).
  0.1::factZ:-or(factA,factC).

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

  query(conclusion).
  
Either 'Greg is a frog' or 'Jessica is a mouse' but not both.