context: Chances are about even that John went to the hallway. It is improbable that Bernhard is a frog. There is little chance that Bill got the milk there. It is probably not the case that if 'John went to the hallway' or 'Bernhard is a frog' or both then Antoine is thirsty. We believe that if either 'Bernhard is a frog' or 'John went to the hallway' but not both then Jessica is a cat. We believe that if 'Bill got the milk there and Bernhard is a frog' then Brian is a rhino.
hypothesis: It is impossible that 'Brian is a rhino and Jessica is a cat'.
valid_hypothesis: It is impossible that 'Brian is a rhino and Jessica is a cat'.
invalid_hypothesis: It is highly likely that 'Brian is a rhino and Jessica is a cat'.
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.
    0.1::factB.
    0.1::factC.
    %hop1
    0.25::factX:-or(factA,factB).
    0.75::factY:-xor(factB,factA).
    0.75::factZ:-and(factC,factB).
  
    %hop2
    conclusion:-and(factZ,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is a rhino and Jessica is a cat'.