context: It is probably not the case that Julius is white. Chances are about even that Lily is gray. There is almost no chance that Winona is a mouse. Chances are about even that if 'Winona is a mouse and Julius is white' then Jeff went to the bedroom. It is probably not the case that if 'Lily is gray and Julius is white' then Bernhard is a swan. We believe that if either 'Winona is a mouse' or 'Julius is white' but not both then Mary put down the apple.
hypothesis: Chances are slight that 'Julius is white' or 'Lily is gray' or both.
valid_hypothesis: There is a better than even chance that 'Julius is white' or 'Lily is gray' or both.
invalid_hypothesis: Chances are slight that 'Julius is white' or 'Lily is gray' 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
    0.25::factA.
    0.5::factB.
    0.02::factC.
    %hop1
    0.5::factX:-and(factC,factA).
    0.25::factY:-and(factB,factA).
    0.75::factZ:-xor(factC,factA).
  
    %hop2
    conclusion:-or(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Julius is white' or 'Lily is gray' or both.