context: It is improbable that Gertrude is a mouse. There is a better than even chance that Mary went to the kitchen. We believe that Fred put down the apple.
hypothesis: There is a better than even chance that 'Mary went to the kitchen' or 'Gertrude is a mouse' or both.
valid_hypothesis: There is a better than even chance that 'Mary went to the kitchen' or 'Gertrude is a mouse' or both.
invalid_hypothesis: It is impossible that 'Mary went to the kitchen' or 'Gertrude is a mouse' 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
    0.1::factA.
    0.6::factB.
    0.75::factC.
    
  
    %hop2
    conclusion:-or(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary went to the kitchen' or 'Gertrude is a mouse' or both.