context: It is unlikely that Mary went to the garden. Chances are about even that Jessica is a mouse. There is a better than even chance that Greg is a swan. It is impossible that if 'Greg is a swan and Mary went to the garden' then Julius is a rhino. It is probably not the case that if 'Greg is a swan and Mary went to the garden' then Lily is a lion. There is a very good chance that if 'Greg is a swan' or 'Jessica is a mouse' or both then John took the apple.
hypothesis: There is a better than even chance that 'Greg is a swan' or 'Lily is a lion' or both.
valid_hypothesis: There is a better than even chance that 'Greg is a swan' or 'Lily is a lion' or both.
invalid_hypothesis: It is highly unlikely that 'Greg is a swan' or 'Lily is a lion' 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
    0.2::factA.
    0.5::factB.
    0.6::factC.
    %hop1
    0.0::factX:-and(factC,factA).
    0.25::factY:-and(factC,factA).
    0.8::factZ:-or(factC,factB).
  
    %hop2
    conclusion:-or(factC,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Greg is a swan' or 'Lily is a lion' or both.