context: Chances are slight that John moved to the garden. There is a very good chance that Gertrude is a sheep. It is likely that Bernhard is a swan.
hypothesis: It is improbable that 'Gertrude is a sheep and Bernhard is a swan'.
valid_hypothesis: There is a better than even chance that 'Gertrude is a sheep and Bernhard is a swan'.
invalid_hypothesis: It is improbable that 'Gertrude is a sheep and Bernhard is a swan'.
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
    0.1::factA.
    0.8::factB.
    0.7::factC.
    
  
    %hop2
    conclusion:-and(factB,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Gertrude is a sheep and Bernhard is a swan'.