context: Chances are about even that Jessica is a mouse. It is certain that Lily is a frog. It is improbable that John went to the kitchen. It is impossible that if 'John went to the kitchen and Lily is a frog' then Bernhard is green. It is probably the case that if 'Jessica is a mouse and John went to the kitchen' then Greg is gray. There is almost no chance that if 'Jessica is a mouse and Lily is a frog' then Sandra left the milk.
hypothesis: It is certain that 'Jessica is a mouse and Lily is a frog'.
valid_hypothesis: Chances are about even that 'Jessica is a mouse and Lily is a frog'.
invalid_hypothesis: It is certain that 'Jessica is a mouse and Lily is a frog'.
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
    0.5::factA.
    1.0::factB.
    0.1::factC.
    %hop1
    0.0::factX:-and(factC,factB).
    0.7::factY:-and(factA,factC).
    0.02::factZ:-and(factA,factB).
  
    %hop2
    conclusion:-and(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Jessica is a mouse and Lily is a frog'.