context: It is probably not the case that Julius is a rhino. We believe that Gertrude is a cat. There is little chance that John discarded the apple.
hypothesis: It is improbable that 'John discarded the apple and Gertrude is a cat'.
valid_hypothesis: It is improbable that 'John discarded the apple and Gertrude is a cat'.
invalid_hypothesis: It is probable that 'John discarded the apple and Gertrude is a cat'.
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
    0.25::factA.
    0.75::factB.
    0.1::factC.
    
  
    %hop2
    conclusion:-and(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'John discarded the apple and Gertrude is a cat'.