context: There is little chance that Julius is a swan. It is almost certain that Winona is a wolf. It is probable that Greg is green. It is impossible that if either 'Greg is green' or 'Julius is a swan' but not both then Lily is a frog. It is likely that if 'Julius is a swan and Winona is a wolf' then Brian is a lion. It is unlikely that if either 'Julius is a swan' or 'Winona is a wolf' but not both then Sandra grabbed the milk.
hypothesis: It is probably not the case that 'Sandra grabbed the milk' or 'Julius is a swan' or both.
valid_hypothesis: It is probably not the case that 'Sandra grabbed the milk' or 'Julius is a swan' or both.
invalid_hypothesis: It is highly likely that 'Sandra grabbed the milk' or 'Julius is a swan' 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
    0.1::factA.
    0.95::factB.
    0.7::factC.
    %hop1
    0.0::factX:-xor(factC,factA).
    0.7::factY:-and(factA,factB).
    0.2::factZ:-xor(factA,factB).
  
    %hop2
    conclusion:-or(factZ,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Sandra grabbed the milk' or 'Julius is a swan' or both.