context: We doubt that Yann is tired. There is almost no chance that Emily is a cat. There is almost no chance that Lily is a rhino. There is little chance that if 'Emily is a cat and Lily is a rhino' then Bernhard is white. It is highly unlikely that if 'Yann is tired and Lily is a rhino' then Jessica is a sheep. It is probable that if either 'Lily is a rhino' or 'Yann is tired' but not both then Daniel dropped the apple.
hypothesis: We doubt that 'Lily is a rhino' or 'Daniel dropped the apple' or both.
valid_hypothesis: We doubt that 'Lily is a rhino' or 'Daniel dropped the apple' or both.
invalid_hypothesis: There is a very good chance that 'Lily is a rhino' or 'Daniel dropped the apple' 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.
    0.02::factB.
    0.02::factC.
    %hop1
    0.1::factX:-and(factB,factC).
    0.05::factY:-and(factA,factC).
    0.7::factZ:-xor(factC,factA).
  
    %hop2
    conclusion:-or(factC,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'Lily is a rhino' or 'Daniel dropped the apple' or both.