context: It is probably not the case that Sandra got the milk. There is a very good chance that Bernhard is gray. There is a better than even chance that Brian is a rhino. It is probable that if either 'Brian is a rhino' or 'Bernhard is gray' but not both then Julius is a frog. It is almost certain that if 'Sandra got the milk' or 'Bernhard is gray' or both then Winona is a cat. It is certain that if either 'Brian is a rhino' or 'Sandra got the milk' but not both then John went to the office.
hypothesis: It is certain that 'Sandra got the milk and Bernhard is gray'.
valid_hypothesis: It is unlikely that 'Sandra got the milk and Bernhard is gray'.
invalid_hypothesis: It is certain that 'Sandra got the milk and Bernhard is gray'.
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.
    0.8::factB.
    0.6::factC.
    %hop1
    0.7::factX:-xor(factC,factB).
    0.95::factY:-or(factA,factB).
    1.0::factZ:-xor(factC,factA).
  
    %hop2
    conclusion:-and(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Sandra got the milk and Bernhard is gray'.