context: It is almost certain that Bernhard is a swan. It is improbable that Jessica is a sheep. We doubt that John went to the bedroom. It is probable that if 'Bernhard is a swan and John went to the bedroom' then Mary dropped the milk. It is certain that if 'Bernhard is a swan and Jessica is a sheep' then Lily is a frog. There is a very good chance that if 'Bernhard is a swan' or 'John went to the bedroom' or both then Julius is white.
hypothesis: It is probably not the case that 'Lily is a frog' or 'John went to the bedroom' or both.
valid_hypothesis: It is probably not the case that 'Lily is a frog' or 'John went to the bedroom' or both.
invalid_hypothesis: It is highly likely that 'Lily is a frog' or 'John went to the bedroom' 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
    0.95::factA.
    0.1::factB.
    0.2::factC.
    %hop1
    0.7::factX:-and(factA,factC).
    1.0::factY:-and(factA,factB).
    0.8::factZ:-or(factA,factC).
  
    %hop2
    conclusion:-or(factY,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Lily is a frog' or 'John went to the bedroom' or both.