context: There is a very good chance that Julius is green. Chances are slight that Bernhard is a swan. There is a better than even chance that Greg is yellow. It is likely that if 'Julius is green and Greg is yellow' then John grabbed the apple. It is likely that if 'Julius is green and Bernhard is a swan' then Mary left the football. It is probable that if 'Bernhard is a swan' or 'Julius is green' or both then Bill went to the garden.
hypothesis: It is highly likely that 'Julius is green and Mary left the football'.
valid_hypothesis: It is highly unlikely that 'Julius is green and Mary left the football'.
invalid_hypothesis: It is highly likely that 'Julius is green and Mary left the football'.
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
    0.8::factA.
    0.1::factB.
    0.6::factC.
    %hop1
    0.7::factX:-and(factA,factC).
    0.7::factY:-and(factA,factB).
    0.7::factZ:-or(factB,factA).
  
    %hop2
    conclusion:-and(factA,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Julius is green and Mary left the football'.