context: Chances are about even that Jason is tired. It is impossible that Mary got the football. It is probably the case that Bernhard is a rhino. It is impossible that if either 'Bernhard is a rhino' or 'Mary got the football' but not both then Julius is yellow. It is probable that if either 'Bernhard is a rhino' or 'Jason is tired' but not both then Lily is white. It is probably the case that if either 'Bernhard is a rhino' or 'Mary got the football' but not both then John went to the bedroom.
hypothesis: It is certain that 'Mary got the football' or 'Lily is white' or both.
valid_hypothesis: It is probably not the case that 'Mary got the football' or 'Lily is white' or both.
invalid_hypothesis: It is certain that 'Mary got the football' or 'Lily is white' or both.
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
    0.5::factA.
    0.0::factB.
    0.7::factC.
    %hop1
    0.0::factX:-xor(factC,factB).
    0.7::factY:-xor(factC,factA).
    0.7::factZ:-xor(factC,factB).
  
    %hop2
    conclusion:-or(factB,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary got the football' or 'Lily is white' or both.