context: It is impossible that Gertrude is a mouse. There is a better than even chance that John put down the apple. There is almost no chance that Julius is green. There is a better than even chance that if 'Julius is green and John put down the apple' then Greg is a frog. Chances are slight that if either 'Gertrude is a mouse' or 'Julius is green' but not both then Mary dropped the milk. We doubt that if 'Julius is green and Gertrude is a mouse' then Jason is bored.
hypothesis: It is probable that 'Mary dropped the milk and Jason is bored'.
valid_hypothesis: It is impossible that 'Mary dropped the milk and Jason is bored'.
invalid_hypothesis: It is probable that 'Mary dropped the milk and Jason is bored'.
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.
    0.6::factB.
    0.02::factC.
    %hop1
    0.6::factX:-and(factC,factB).
    0.1::factY:-xor(factA,factC).
    0.2::factZ:-and(factC,factA).
  
    %hop2
    conclusion:-and(factY,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary dropped the milk and Jason is bored'.