context: There is almost no chance that Jeff moved to the garden. Chances are about even that Julius is a rhino. It is almost certain that Daniel dropped the apple. It is improbable that if 'Daniel dropped the apple' or 'Julius is a rhino' or both then Greg is a lion. There is a better than even chance that if 'Daniel dropped the apple' or 'Julius is a rhino' or both then John went to the bedroom. It is impossible that if 'Daniel dropped the apple and Julius is a rhino' then Gertrude is a cat.
hypothesis: There is a very good chance that 'John went to the bedroom' or 'Julius is a rhino' or both.
valid_hypothesis: There is a very good chance that 'John went to the bedroom' or 'Julius is a rhino' or both.
invalid_hypothesis: It is highly unlikely that 'John went to the bedroom' or 'Julius is a rhino' 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
    0.02::factA.
    0.5::factB.
    0.95::factC.
    %hop1
    0.1::factX:-or(factC,factB).
    0.6::factY:-or(factC,factB).
    0.0::factZ:-and(factC,factB).
  
    %hop2
    conclusion:-or(factY,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'John went to the bedroom' or 'Julius is a rhino' or both.