context: Chances are slight that John discarded the apple. It is almost certain that Brian is a rhino. Chances are slight that Mary got the football. We believe that if 'Brian is a rhino' or 'John discarded the apple' or both then Winona is a mouse. It is likely that if 'John discarded the apple and Mary got the football' then Lily is white. It is probable that if 'Mary got the football and Brian is a rhino' then Bernhard is white.
hypothesis: It is highly likely that 'Bernhard is white and John discarded the apple'.
valid_hypothesis: It is impossible that 'Bernhard is white and John discarded the apple'.
invalid_hypothesis: It is highly likely that 'Bernhard is white and John discarded the apple'.
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.
    0.95::factB.
    0.1::factC.
    %hop1
    0.75::factX:-or(factB,factA).
    0.7::factY:-and(factA,factC).
    0.7::factZ:-and(factC,factB).
  
    %hop2
    conclusion:-and(factZ,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is white and John discarded the apple'.