context: We doubt that Julius is yellow. There is a better than even chance that Bernhard is white. It is unlikely that Brian is a rhino. Chances are slight that if 'Julius is yellow and Bernhard is white' then Sandra left the milk. It is almost certain that if either 'Julius is yellow' or 'Brian is a rhino' but not both then Mary went to the kitchen. It is impossible that if 'Julius is yellow' or 'Bernhard is white' or both then John moved to the office.
hypothesis: It is unlikely that 'Sandra left the milk' or 'Julius is yellow' or both.
valid_hypothesis: It is unlikely that 'Sandra left the milk' or 'Julius is yellow' or both.
invalid_hypothesis: It is likely that 'Sandra left the milk' or 'Julius is yellow' 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
    0.2::factA.
    0.6::factB.
    0.2::factC.
    %hop1
    0.1::factX:-and(factA,factB).
    0.95::factY:-xor(factA,factC).
    0.0::factZ:-or(factA,factB).
  
    %hop2
    conclusion:-or(factX,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Sandra left the milk' or 'Julius is yellow' or both.