context: It is impossible that Julius is a rhino. There is little chance that Sandra dropped the milk. It is probably the case that John moved to the office. It is highly likely that if 'Julius is a rhino' or 'John moved to the office' or both then Sumit is thirsty. It is highly unlikely that if either 'Julius is a rhino' or 'John moved to the office' but not both then Jessica is a cat. There is little chance that if either 'Sandra dropped the milk' or 'John moved to the office' but not both then Lily is a lion.
hypothesis: There is a better than even chance that either 'Sumit is thirsty' or 'Julius is a rhino' but not both.
valid_hypothesis: There is a better than even chance that either 'Sumit is thirsty' or 'Julius is a rhino' but not both.
invalid_hypothesis: It is impossible that either 'Sumit is thirsty' or 'Julius is a rhino' 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
    0.0::factA.
    0.1::factB.
    0.7::factC.
    %hop1
    0.9::factX:-or(factA,factC).
    0.05::factY:-xor(factA,factC).
    0.1::factZ:-xor(factB,factC).
  
    %hop2
    conclusion:-xor(factX,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Sumit is thirsty' or 'Julius is a rhino' but not both.