context: There is little chance that Julius is yellow. There is a very good chance that Jessica is a sheep. There is a very good chance that Greg is green. There is little chance that if 'Greg is green' or 'Jessica is a sheep' or both then Bernhard is gray. There is a very good chance that if either 'Greg is green' or 'Jessica is a sheep' but not both then Lily is a rhino. We doubt that if 'Greg is green and Julius is yellow' then Sandra put down the milk.
hypothesis: It is probably not the case that 'Bernhard is gray' or 'Lily is a rhino' or both.
valid_hypothesis: It is probably not the case that 'Bernhard is gray' or 'Lily is a rhino' or both.
invalid_hypothesis: It is probably the case that 'Bernhard is gray' or 'Lily 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
    0.1::factA.
    0.8::factB.
    0.8::factC.
    %hop1
    0.1::factX:-or(factC,factB).
    0.8::factY:-xor(factC,factB).
    0.2::factZ:-and(factC,factA).
  
    %hop2
    conclusion:-or(factX,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is gray' or 'Lily is a rhino' or both.