context: It is certain that Sandra left the apple. It is highly likely that Bernhard is a swan. There is a very good chance that Lily is a frog. It is impossible that if 'Sandra left the apple' or 'Bernhard is a swan' or both then Emily is a wolf. It is highly likely that if 'Lily is a frog' or 'Sandra left the apple' or both then Julius is a swan. There is a very good chance that if either 'Lily is a frog' or 'Bernhard is a swan' but not both then John went to the office.
hypothesis: It is unlikely that either 'Bernhard is a swan' or 'Emily is a wolf' but not both.
valid_hypothesis: It is highly likely that either 'Bernhard is a swan' or 'Emily is a wolf' but not both.
invalid_hypothesis: It is unlikely that either 'Bernhard is a swan' or 'Emily is a wolf' 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
    1.0::factA.
    0.9::factB.
    0.8::factC.
    %hop1
    0.0::factX:-or(factA,factB).
    0.9::factY:-or(factC,factA).
    0.8::factZ:-xor(factC,factB).
  
    %hop2
    conclusion:-xor(factB,factX).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Bernhard is a swan' or 'Emily is a wolf' but not both.