context: It is probably the case that Lily is a swan. It is probable that Mary got the football. It is probably not the case that Bernhard is a frog.
hypothesis: There is almost no chance that 'Bernhard is a frog' or 'Lily is a swan' or both.
valid_hypothesis: There is a very good chance that 'Bernhard is a frog' or 'Lily is a swan' or both.
invalid_hypothesis: There is almost no chance that 'Bernhard is a frog' or 'Lily 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
    0.7::factA.
    0.7::factB.
    0.25::factC.
    
  
    %hop2
    conclusion:-or(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is a frog' or 'Lily is a swan' or both.