context: It is likely that Lily is green. We believe that Mary left the football. Chances are slight that Sandra got the football. It is probable that if either 'Mary left the football' or 'Sandra got the football' but not both then Jason is tired. It is probable that if 'Lily is green and Mary left the football' then Greg is a swan. It is almost certain that if 'Lily is green' or 'Sandra got the football' or both then Brian is a frog.
hypothesis: It is almost certain that 'Lily is green and Sandra got the football'.
valid_hypothesis: It is highly unlikely that 'Lily is green and Sandra got the football'.
invalid_hypothesis: It is almost certain that 'Lily is green and Sandra got 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
    0.7::factA.
    0.75::factB.
    0.1::factC.
    %hop1
    0.7::factX:-xor(factB,factC).
    0.7::factY:-and(factA,factB).
    0.95::factZ:-or(factA,factC).
  
    %hop2
    conclusion:-and(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Lily is green and Sandra got the football'.