context: It is highly likely that Bernhard is a swan. There is little chance that John went to the office. It is probably the case that Brian is yellow. It is probable that if either 'Bernhard is a swan' or 'Brian is yellow' but not both then Winona is a mouse. We believe that if either 'Bernhard is a swan' or 'Brian is yellow' but not both then Lily is gray. It is highly likely that if 'Brian is yellow' or 'Bernhard is a swan' or both then Julius is white.
hypothesis: Chances are about even that 'Winona is a mouse and Brian is yellow'.
valid_hypothesis: It is highly unlikely that 'Winona is a mouse and Brian is yellow'.
invalid_hypothesis: Chances are about even that 'Winona is a mouse and Brian is yellow'.
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
    0.9::factA.
    0.1::factB.
    0.7::factC.
    %hop1
    0.7::factX:-xor(factA,factC).
    0.75::factY:-xor(factA,factC).
    0.9::factZ:-or(factC,factA).
  
    %hop2
    conclusion:-and(factX,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Winona is a mouse and Brian is yellow'.