context: It is probably not the case that Greg is white. It is likely that Julius is a frog. It is probably not the case that Lily is a rhino. It is probable that if either 'Greg is white' or 'Julius is a frog' but not both then John dropped the apple. It is probable that if 'Greg is white' or 'Lily is a rhino' or both then Mary moved to the office. We believe that if 'Greg is white and Lily is a rhino' then Jeff left the apple.
hypothesis: Chances are slight that either 'Lily is a rhino' or 'Julius is a frog' but not both.
valid_hypothesis: There is a better than even chance that either 'Lily is a rhino' or 'Julius is a frog' but not both.
invalid_hypothesis: Chances are slight that either 'Lily is a rhino' or 'Julius is a frog' 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
    0.25::factA.
    0.7::factB.
    0.25::factC.
    %hop1
    0.7::factX:-xor(factA,factB).
    0.7::factY:-or(factA,factC).
    0.75::factZ:-and(factA,factC).
  
    %hop2
    conclusion:-xor(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Lily is a rhino' or 'Julius is a frog' but not both.