context: Chances are slight that Julius is a swan. We believe that Lily is a lion. It is highly likely that Mary left the football. It is probably the case that if either 'Lily is a lion' or 'Julius is a swan' but not both then Winona is a mouse. We doubt that if 'Lily is a lion and Mary left the football' then Sandra took the apple. It is probable that if either 'Julius is a swan' or 'Lily is a lion' but not both then Emily is a wolf.
hypothesis: There is almost no chance that 'Emily is a wolf' or 'Julius is a swan' or both.
valid_hypothesis: There is a better than even chance that 'Emily is a wolf' or 'Julius is a swan' or both.
invalid_hypothesis: There is almost no chance 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
    0.1::factA.
    0.75::factB.
    0.9::factC.
    %hop1
    0.7::factX:-xor(factB,factA).
    0.2::factY:-and(factB,factC).
    0.7::factZ:-xor(factA,factB).
  
    %hop2
    conclusion:-or(factZ,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Emily is a wolf' or 'Julius is a swan' or both.