context: It is impossible that Bernhard is a frog. There is almost no chance that Yann is hungry. There is little chance that Mary went to the bedroom. It is certain that if 'Yann is hungry and Bernhard is a frog' then Emily is a wolf. There is a better than even chance that if either 'Mary went to the bedroom' or 'Yann is hungry' but not both then Jessica is a cat. It is probably not the case that if either 'Yann is hungry' or 'Mary went to the bedroom' but not both then Brian is gray.
hypothesis: It is almost certain that either 'Yann is hungry' or 'Brian is gray' but not both.
valid_hypothesis: It is highly unlikely that either 'Yann is hungry' or 'Brian is gray' but not both.
invalid_hypothesis: It is almost certain that either 'Yann is hungry' or 'Brian 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
    0.0::factA.
    0.02::factB.
    0.1::factC.
    %hop1
    1.0::factX:-and(factB,factA).
    0.6::factY:-xor(factC,factB).
    0.25::factZ:-xor(factB,factC).
  
    %hop2
    conclusion:-xor(factB,factZ).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Yann is hungry' or 'Brian is gray' but not both.