context: It is probable that Gertrude is a wolf. It is highly unlikely that Lily is green. It is certain that Greg is a rhino. There is a very good chance that if 'Gertrude is a wolf' or 'Lily is green' or both then Daniel dropped the milk. It is highly likely that if 'Greg is a rhino and Gertrude is a wolf' then Jeff went to the hallway. There is a very good chance that if 'Gertrude is a wolf' or 'Greg is a rhino' or both then Bernhard is a lion.
hypothesis: It is probable that 'Daniel dropped the milk' or 'Gertrude is a wolf' or both.
valid_hypothesis: It is probable that 'Daniel dropped the milk' or 'Gertrude is a wolf' or both.
invalid_hypothesis: It is impossible that 'Daniel dropped the milk' or 'Gertrude is a wolf' or 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
    0.7::factA.
    0.05::factB.
    1.0::factC.
    %hop1
    0.8::factX:-or(factA,factB).
    0.9::factY:-and(factC,factA).
    0.8::factZ:-or(factA,factC).
  
    %hop2
    conclusion:-or(factX,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Daniel dropped the milk' or 'Gertrude is a wolf' or both.