context: It is certain that Julius is a swan. It is highly unlikely that Sandra took the football. There is a very good chance that John moved to the garden. It is probably not the case that if 'Sandra took the football and Julius is a swan' then Greg is yellow. Chances are about even that if 'Julius is a swan and Sandra took the football' then Bernhard is a rhino. It is likely that if either 'John moved to the garden' or 'Julius is a swan' but not both then Mary left the milk.
hypothesis: It is improbable that 'Sandra took the football' or 'Julius is a swan' or both.
valid_hypothesis: It is certain that 'Sandra took the football' or 'Julius is a swan' or both.
invalid_hypothesis: It is improbable that 'Sandra took the football' or 'Julius is a swan' 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
    1.0::factA.
    0.05::factB.
    0.8::factC.
    %hop1
    0.25::factX:-and(factB,factA).
    0.5::factY:-and(factA,factB).
    0.7::factZ:-xor(factC,factA).
  
    %hop2
    conclusion:-or(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Sandra took the football' or 'Julius is a swan' or both.