context: It is likely that Jessica is a mouse. It is highly unlikely that Greg is a swan. We believe that John went to the kitchen. Chances are slight that if 'John went to the kitchen and Jessica is a mouse' then Mary is in the school. We doubt that if 'Greg is a swan and John went to the kitchen' then Bernhard is a frog. It is improbable that if 'Greg is a swan and Jessica is a mouse' then Lily is a rhino.
hypothesis: It is probable that 'Bernhard is a frog and Jessica is a mouse'.
valid_hypothesis: It is impossible that 'Bernhard is a frog and Jessica is a mouse'.
invalid_hypothesis: It is probable that 'Bernhard is a frog and Jessica is a mouse'.
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
    0.7::factA.
    0.05::factB.
    0.75::factC.
    %hop1
    0.1::factX:-and(factC,factA).
    0.2::factY:-and(factB,factC).
    0.1::factZ:-and(factB,factA).
  
    %hop2
    conclusion:-and(factY,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is a frog and Jessica is a mouse'.