context: It is highly unlikely that Jeff went to the garden. It is almost certain that Julius is white. We doubt that Lily is a swan. It is impossible that if 'Lily is a swan' or 'Julius is white' or both then Gertrude is a cat. We doubt that if 'Lily is a swan' or 'Julius is white' or both then John moved to the office. It is probably not the case that if 'Julius is white and Lily is a swan' then Brian is yellow.
hypothesis: We believe that 'John moved to the office' or 'Brian is yellow' or both.
valid_hypothesis: It is probably not the case that 'John moved to the office' or 'Brian is yellow' or both.
invalid_hypothesis: We believe that 'John moved to the office' or 'Brian is yellow' 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
    0.05::factA.
    0.95::factB.
    0.2::factC.
    %hop1
    0.0::factX:-or(factC,factB).
    0.2::factY:-or(factC,factB).
    0.25::factZ:-and(factB,factC).
  
    %hop2
    conclusion:-or(factY,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'John moved to the office' or 'Brian is yellow' or both.