context: There is a very good chance that Greg is a swan. We believe that Sandra dropped the milk. It is probably the case that Brian is a rhino. It is probably not the case that if either 'Brian is a rhino' or 'Greg is a swan' but not both then Yann is tired. It is almost certain that if either 'Greg is a swan' or 'Brian is a rhino' but not both then Lily is white. There is a very good chance that if 'Brian is a rhino' or 'Sandra dropped the milk' or both then John went to the kitchen.
hypothesis: There is almost no chance that 'John went to the kitchen' or 'Lily is white' or both.
valid_hypothesis: It is highly likely that 'John went to the kitchen' or 'Lily is white' or both.
invalid_hypothesis: There is almost no chance that 'John went to the kitchen' or 'Lily is white' 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
    0.8::factA.
    0.75::factB.
    0.7::factC.
    %hop1
    0.25::factX:-xor(factC,factA).
    0.95::factY:-xor(factA,factC).
    0.8::factZ:-or(factC,factB).
  
    %hop2
    conclusion:-or(factZ,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'John went to the kitchen' or 'Lily is white' or both.