context: It is probable that Greg is green. There is almost no chance that Gertrude is a mouse. We believe that John dropped the apple. We doubt that if 'Gertrude is a mouse' or 'Greg is green' or both then Lily is a lion. It is probable that if 'Gertrude is a mouse' or 'Greg is green' or both then Yann is tired. It is unlikely that if either 'Greg is green' or 'Gertrude is a mouse' but not both then Bernhard is a swan.
hypothesis: It is highly likely that 'Yann is tired and Lily is a lion'.
valid_hypothesis: There is little chance that 'Yann is tired and Lily is a lion'.
invalid_hypothesis: It is highly likely that 'Yann is tired and Lily is a lion'.
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.
    0.02::factB.
    0.75::factC.
    %hop1
    0.2::factX:-or(factB,factA).
    0.7::factY:-or(factB,factA).
    0.2::factZ:-xor(factA,factB).
  
    %hop2
    conclusion:-and(factY,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'Yann is tired and Lily is a lion'.