context: There is a better than even chance that Greg is a rhino. It is almost certain that Brian is yellow. It is almost certain that John went to the hallway. It is highly unlikely that if 'Brian is yellow' or 'Greg is a rhino' or both then Sandra left the football. It is unlikely that if 'John went to the hallway' or 'Greg is a rhino' or both then Gertrude is a cat. There is a better than even chance that if either 'John went to the hallway' or 'Brian is yellow' but not both then Bernhard is a frog.
hypothesis: It is almost certain that 'Brian is yellow' or 'Gertrude is a cat' or both.
valid_hypothesis: It is almost certain that 'Brian is yellow' or 'Gertrude is a cat' or both.
invalid_hypothesis: It is unlikely that 'Brian is yellow' or 'Gertrude is a cat' 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
    0.6::factA.
    0.95::factB.
    0.95::factC.
    %hop1
    0.05::factX:-or(factB,factA).
    0.2::factY:-or(factC,factA).
    0.6::factZ:-xor(factC,factB).
  
    %hop2
    conclusion:-or(factB,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is yellow' or 'Gertrude is a cat' or both.