context: It is certain that Bernhard is gray. It is highly unlikely that Gertrude is a mouse. There is a very good chance that Brian is a rhino.
hypothesis: Chances are slight that 'Gertrude is a mouse' or 'Brian is a rhino' or both.
valid_hypothesis: There is a very good chance that 'Gertrude is a mouse' or 'Brian is a rhino' or both.
invalid_hypothesis: Chances are slight that 'Gertrude is a mouse' or 'Brian is a rhino' 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
    1.0::factA.
    0.05::factB.
    0.8::factC.
    
  
    %hop2
    conclusion:-or(factB,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Gertrude is a mouse' or 'Brian is a rhino' or both.