context: It is highly unlikely that Bernhard is green. We believe that Jeff moved to the office. It is highly likely that Brian is yellow.
hypothesis: We believe that either 'Bernhard is green' or 'Jeff moved to the office' but not both.
valid_hypothesis: We believe that either 'Bernhard is green' or 'Jeff moved to the office' but not both.
invalid_hypothesis: Chances are slight that either 'Bernhard is green' or 'Jeff moved to the office' but not 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
    0.05::factA.
    0.75::factB.
    0.9::factC.
    
  
    %hop2
    conclusion:-xor(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Bernhard is green' or 'Jeff moved to the office' but not both.