context: It is unlikely that Brian is a rhino. We believe that Gertrude is a sheep. It is impossible that John moved to the office. There is little chance that if either 'Brian is a rhino' or 'John moved to the office' but not both then Bernhard is green. Chances are about even that if 'Brian is a rhino' or 'Gertrude is a sheep' or both then Emily is a wolf. There is almost no chance that if 'Brian is a rhino and Gertrude is a sheep' then Lily is a rhino.
hypothesis: There is a very good chance that 'Bernhard is green' or 'Brian is a rhino' or both.
valid_hypothesis: We doubt that 'Bernhard is green' or 'Brian is a rhino' or both.
invalid_hypothesis: There is a very good chance that 'Bernhard is green' or 'Brian 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
    0.2::factA.
    0.75::factB.
    0.0::factC.
    %hop1
    0.1::factX:-xor(factA,factC).
    0.5::factY:-or(factA,factB).
    0.02::factZ:-and(factA,factB).
  
    %hop2
    conclusion:-or(factX,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is green' or 'Brian is a rhino' or both.