context: It is impossible that Mary went to the garden. It is impossible that Winona is a wolf. Chances are slight that Lily is a swan. There is a very good chance that if 'Mary went to the garden' or 'Winona is a wolf' or both then Emily is a sheep. It is improbable that if 'Lily is a swan' or 'Mary went to the garden' or both then Bernhard is gray. It is probable that if either 'Winona is a wolf' or 'Lily is a swan' but not both then Sandra got the milk.
hypothesis: Chances are about even that 'Winona is a wolf and Bernhard is gray'.
valid_hypothesis: It is impossible that 'Winona is a wolf and Bernhard is gray'.
invalid_hypothesis: Chances are about even that 'Winona is a wolf and Bernhard is gray'.
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.
    0.0::factB.
    0.1::factC.
    %hop1
    0.8::factX:-or(factA,factB).
    0.1::factY:-or(factC,factA).
    0.7::factZ:-xor(factB,factC).
  
    %hop2
    conclusion:-and(factB,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Winona is a wolf and Bernhard is gray'.