context: It is highly unlikely that Mary moved to the office. There is almost no chance that Lily is gray. It is highly likely that Emily is a mouse. There is a very good chance that if 'Lily is gray' or 'Emily is a mouse' or both then Winona is a sheep. Chances are about even that if 'Mary moved to the office and Lily is gray' then Julius is yellow. It is highly unlikely that if 'Mary moved to the office and Emily is a mouse' then Brian is white.
hypothesis: It is impossible that 'Brian is white and Emily is a mouse'.
valid_hypothesis: It is impossible that 'Brian is white and Emily is a mouse'.
invalid_hypothesis: It is certain that 'Brian is white and Emily is a mouse'.
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
    0.05::factA.
    0.02::factB.
    0.9::factC.
    %hop1
    0.8::factX:-or(factB,factC).
    0.5::factY:-and(factA,factB).
    0.05::factZ:-and(factA,factC).
  
    %hop2
    conclusion:-and(factZ,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is white and Emily is a mouse'.