context: It is probable that Winona is a wolf. Chances are slight that Julius is a frog. It is probable that Bernhard is gray. It is probably not the case that if 'Julius is a frog and Winona is a wolf' then Brian is yellow. There is little chance that if either 'Winona is a wolf' or 'Julius is a frog' but not both then Mary left the milk. There is little chance that if either 'Bernhard is gray' or 'Winona is a wolf' but not both then Lily is white.
hypothesis: It is highly likely that 'Mary left the milk and Bernhard is gray'.
valid_hypothesis: It is highly unlikely that 'Mary left the milk and Bernhard is gray'.
invalid_hypothesis: It is highly likely that 'Mary left 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
    0.7::factA.
    0.1::factB.
    0.7::factC.
    %hop1
    0.25::factX:-and(factB,factA).
    0.1::factY:-xor(factA,factB).
    0.1::factZ:-xor(factC,factA).
  
    %hop2
    conclusion:-and(factY,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary left the milk and Bernhard is gray'.