context: There is a better than even chance that Mary took the milk. It is impossible that Antoine is hungry. We believe that Lily is a swan. Chances are slight that if 'Lily is a swan and Mary took the milk' then Bernhard is green. It is certain that if 'Mary took the milk and Lily is a swan' then John went to the office. It is probable that if either 'Antoine is hungry' or 'Mary took the milk' but not both then Greg is a lion.
hypothesis: It is impossible that 'Mary took the milk and Antoine is hungry'.
valid_hypothesis: It is impossible that 'Mary took the milk and Antoine is hungry'.
invalid_hypothesis: It is almost certain that 'Mary took the milk and Antoine is hungry'.
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
    0.6::factA.
    0.0::factB.
    0.75::factC.
    %hop1
    0.1::factX:-and(factC,factA).
    1.0::factY:-and(factA,factC).
    0.7::factZ:-xor(factB,factA).
  
    %hop2
    conclusion:-and(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary took the milk and Antoine is hungry'.