It is probably not the case that Gertrude is a sheep. We doubt that Julius is a lion. It is highly likely that John discarded the apple. It is likely that if either 'Gertrude is a sheep' or 'Julius is a lion' but not both then Jeff moved to the office. It is certain that if either 'Gertrude is a sheep' or 'John discarded the apple' but not both then Brian is gray. It is probable that if 'John discarded the apple and Julius is a lion' then Winona is a mouse.
It is highly unlikely that 'Winona is a mouse and Jeff moved to the office'.
It is highly unlikely that 'Winona is a mouse and Jeff moved to the office'.
We believe that 'Winona is a mouse and Jeff moved to the office'.

  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
  0.25::factA.
  0.2::factB.
  0.9::factC.
  %hop1
  0.7::factX:-xor(factA,factB).
  1.0::factY:-xor(factA,factC).
  0.7::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Winona is a mouse and Jeff moved to the office'.