context: There is a better than even chance that Lily is gray. It is almost certain that Jessica is a mouse. It is highly unlikely that Julius is a rhino. It is improbable that if 'Julius is a rhino' or 'Jessica is a mouse' or both then Sandra dropped the apple. It is highly likely that if either 'Lily is gray' or 'Jessica is a mouse' but not both then John went to the office. It is impossible that if 'Jessica is a mouse' or 'Julius is a rhino' or both then Brian is white.
hypothesis: There is a better than even chance that either 'Brian is white' or 'Lily is gray' but not both.
valid_hypothesis: There is a better than even chance that either 'Brian is white' or 'Lily is gray' but not both.
invalid_hypothesis: It is highly unlikely that either 'Brian is white' or 'Lily is gray' 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
    0.6::factA.
    0.95::factB.
    0.05::factC.
    %hop1
    0.1::factX:-or(factC,factB).
    0.9::factY:-xor(factA,factB).
    0.0::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-xor(factZ,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Brian is white' or 'Lily is gray' but not both.