context: Chances are about even that Bill moved to the office. It is highly unlikely that Brian is green. It is almost certain that Bernhard is white. It is probably not the case that if 'Bill moved to the office and Bernhard is white' then Winona is a wolf. It is certain that if 'Bill moved to the office and Brian is green' then Gertrude is a mouse. It is highly unlikely that if either 'Bernhard is white' or 'Brian is green' but not both then Mary put down the apple.
hypothesis: It is certain that 'Mary put down the apple and Bill moved to the office'.
valid_hypothesis: There is almost no chance that 'Mary put down the apple and Bill moved to the office'.
invalid_hypothesis: It is certain that 'Mary put down the apple and Bill moved to the office'.
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.
    0.05::factB.
    0.95::factC.
    %hop1
    0.25::factX:-and(factA,factC).
    1.0::factY:-and(factA,factB).
    0.05::factZ:-xor(factC,factB).
  
    %hop2
    conclusion:-and(factZ,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary put down the apple and Bill moved to the office'.