context: It is certain that Bernhard is green. It is probably the case that Winona is a sheep. There is a very good chance that Greg is a lion. It is probably the case that if 'Bernhard is green and Winona is a sheep' then John put down the apple. It is certain that if either 'Greg is a lion' or 'Bernhard is green' but not both then Sandra dropped the milk. It is likely that if 'Greg is a lion' or 'Bernhard is green' or both then Lily is a swan.
hypothesis: There is almost no chance that 'Greg is a lion' or 'John put down the apple' or both.
valid_hypothesis: It is highly likely that 'Greg is a lion' or 'John put down the apple' or both.
invalid_hypothesis: There is almost no chance that 'Greg is a lion' or 'John put down the apple' 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.
    0.7::factB.
    0.8::factC.
    %hop1
    0.7::factX:-and(factA,factB).
    1.0::factY:-xor(factC,factA).
    0.7::factZ:-or(factC,factA).
  
    %hop2
    conclusion:-or(factC,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'Greg is a lion' or 'John put down the apple' or both.