context: It is unlikely that Emily is a cat. There is almost no chance that Julius is a lion. There is a very good chance that John moved to the office. It is likely that if 'Julius is a lion and John moved to the office' then Bernhard is a swan. It is probably not the case that if either 'Emily is a cat' or 'Julius is a lion' but not both then Daniel dropped the apple. It is highly likely that if 'Julius is a lion' or 'John moved to the office' or both then Gertrude is a mouse.
hypothesis: It is probably the case that either 'Gertrude is a mouse' or 'Julius is a lion' but not both.
valid_hypothesis: It is probably the case that either 'Gertrude is a mouse' or 'Julius is a lion' but not both.
invalid_hypothesis: It is unlikely that either 'Gertrude is a mouse' or 'Julius is a lion' but not both.
problog: 
    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
    0.2::factA.
    0.02::factB.
    0.8::factC.
    %hop1
    0.7::factX:-and(factB,factC).
    0.25::factY:-xor(factA,factB).
    0.9::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-xor(factZ,factB).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Gertrude is a mouse' or 'Julius is a lion' but not both.