context: It is probably not the case that Greg is a frog. It is probably the case that Brian is white. We believe that Antoine is hungry. It is probable that if 'Antoine is hungry and Greg is a frog' then Lily is a lion. Chances are slight that if either 'Antoine is hungry' or 'Greg is a frog' but not both then Julius is yellow. It is improbable that if 'Brian is white and Antoine is hungry' then John went to the bedroom.
hypothesis: There is a better than even chance that either 'John went to the bedroom' or 'Brian is white' but not both.
valid_hypothesis: There is a better than even chance that either 'John went to the bedroom' or 'Brian is white' but not both.
invalid_hypothesis: It is impossible that either 'John went to the bedroom' or 'Brian is white' 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.
    0.75::factC.
    %hop1
    0.7::factX:-and(factC,factA).
    0.1::factY:-xor(factC,factA).
    0.1::factZ:-and(factB,factC).
  
    %hop2
    conclusion:-xor(factZ,factB).
  
    query(conclusion).
    
hypothesis_assertion: Either 'John went to the bedroom' or 'Brian is white' but not both.