context: There is a very good chance that Daniel grabbed the apple. There is a very good chance that Lily is a swan. It is probably the case that Mary went to the office. It is probably the case that if 'Lily is a swan and Daniel grabbed the apple' then Bernhard is green. It is probably not the case that if either 'Mary went to the office' or 'Lily is a swan' but not both then Julius is gray. It is highly likely that if 'Lily is a swan' or 'Mary went to the office' or both then Brian is a swan.
hypothesis: It is unlikely that 'Mary went to the office' or 'Brian is a swan' or both.
valid_hypothesis: It is highly likely that 'Mary went to the office' or 'Brian is a swan' or both.
invalid_hypothesis: It is unlikely that 'Mary went to the office' or 'Brian 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
    0.8::factA.
    0.8::factB.
    0.7::factC.
    %hop1
    0.7::factX:-and(factB,factA).
    0.25::factY:-xor(factC,factB).
    0.9::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-or(factC,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary went to the office' or 'Brian is a swan' or both.