context: It is almost certain that Greg is a frog. It is certain that Jessica is a cat. There is a better than even chance that Bernhard is a frog. There is little chance that if either 'Greg is a frog' or 'Bernhard is a frog' but not both then Emily is a wolf. There is a very good chance that if 'Bernhard is a frog and Jessica is a cat' then John picked up the apple. Chances are slight that if either 'Jessica is a cat' or 'Greg is a frog' but not both then Julius is a swan.
hypothesis: It is likely that 'Emily is a wolf' or 'Julius is a swan' or both.
valid_hypothesis: It is highly unlikely that 'Emily is a wolf' or 'Julius is a swan' or both.
invalid_hypothesis: It is likely that 'Emily is a wolf' or 'Julius is a swan' or 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
    0.95::factA.
    1.0::factB.
    0.6::factC.
    %hop1
    0.1::factX:-xor(factA,factC).
    0.8::factY:-and(factC,factB).
    0.1::factZ:-xor(factB,factA).
  
    %hop2
    conclusion:-or(factX,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'Emily is a wolf' or 'Julius is a swan' or both.