context: Chances are slight that Sandra got the milk. There is a better than even chance that Julius is yellow. It is highly likely that John moved to the garden. It is likely that if either 'John moved to the garden' or 'Sandra got the milk' but not both then Bernhard is a rhino. We believe that if 'Julius is yellow and Sandra got the milk' then Brian is a frog. It is probable that if either 'Julius is yellow' or 'Sandra got the milk' but not both then Mary left the football.
hypothesis: There is almost no chance that 'Julius is yellow and John moved to the garden'.
valid_hypothesis: Chances are about even that 'Julius is yellow and John moved to the garden'.
invalid_hypothesis: There is almost no chance that 'Julius is yellow and John moved to the garden'.
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
    0.1::factA.
    0.6::factB.
    0.9::factC.
    %hop1
    0.7::factX:-xor(factC,factA).
    0.75::factY:-and(factB,factA).
    0.7::factZ:-xor(factB,factA).
  
    %hop2
    conclusion:-and(factB,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Julius is yellow and John moved to the garden'.