It is impossible that John went to the hallway. There is almost no chance that Emily is a sheep. It is probably not the case that Jessica is a mouse. It is highly unlikely that if either 'Emily is a sheep' or 'Jessica is a mouse' but not both then Lily is white. It is likely that if 'John went to the hallway' or 'Emily is a sheep' or both then Bernhard is a swan. It is probably the case that if either 'Jessica is a mouse' or 'John went to the hallway' but not both then Julius is a frog.
We doubt that 'Bernhard is a swan' or 'Julius is a frog' or both.
We doubt that 'Bernhard is a swan' or 'Julius is a frog' or both.
It is highly likely that 'Bernhard is a swan' or 'Julius is a frog' 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
  0.0::factA.
  0.02::factB.
  0.25::factC.
  %hop1
  0.05::factX:-xor(factB,factC).
  0.7::factY:-or(factA,factB).
  0.7::factZ:-xor(factC,factA).

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

  query(conclusion).
  
'Bernhard is a swan' or 'Julius is a frog' or both.