context: There is a very good chance that John picked up the apple. It is likely that Gertrude is a sheep. It is highly unlikely that Julius is a lion. It is unlikely that if 'John picked up the apple' or 'Gertrude is a sheep' or both then Jeff went to the garden. There is almost no chance that if either 'Julius is a lion' or 'Gertrude is a sheep' but not both then Bernhard is a frog. We believe that if either 'John picked up the apple' or 'Julius is a lion' but not both then Mary dropped the milk.
hypothesis: It is highly likely that 'Bernhard is a frog' or 'Jeff went to the garden' or both.
valid_hypothesis: We doubt that 'Bernhard is a frog' or 'Jeff went to the garden' or both.
invalid_hypothesis: It is highly likely that 'Bernhard is a frog' or 'Jeff went to the garden' 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
    0.8::factA.
    0.7::factB.
    0.05::factC.
    %hop1
    0.2::factX:-or(factA,factB).
    0.02::factY:-xor(factC,factB).
    0.75::factZ:-xor(factA,factC).
  
    %hop2
    conclusion:-or(factY,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is a frog' or 'Jeff went to the garden' or both.