context: Chances are about even that Julius is gray. Chances are slight that Emily is a mouse. It is highly likely that Bernhard is gray. We doubt that if 'Julius is gray and Emily is a mouse' then Mary dropped the apple. It is certain that if either 'Emily is a mouse' or 'Bernhard is gray' but not both then Sandra got the football. It is improbable that if 'Emily is a mouse' or 'Bernhard is gray' or both then John went to the bedroom.
hypothesis: It is almost certain that 'Bernhard is gray' or 'Julius is gray' or both.
valid_hypothesis: It is almost certain that 'Bernhard is gray' or 'Julius is gray' or both.
invalid_hypothesis: It is impossible that 'Bernhard is gray' or 'Julius 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
    0.5::factA.
    0.1::factB.
    0.9::factC.
    %hop1
    0.2::factX:-and(factA,factB).
    1.0::factY:-xor(factB,factC).
    0.1::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-or(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is gray' or 'Julius is gray' or both.