context: It is impossible that Jeff left the apple. It is probable that Mary went to the garden. It is highly likely that Gertrude is a wolf. There is almost no chance that if either 'Jeff left the apple' or 'Mary went to the garden' but not both then Greg is white. There is little chance that if 'Jeff left the apple' or 'Gertrude is a wolf' or both then Brian is green. It is impossible that if 'Mary went to the garden and Jeff left the apple' then Julius is yellow.
hypothesis: It is improbable that 'Gertrude is a wolf' or 'Brian is green' or both.
valid_hypothesis: It is highly likely that 'Gertrude is a wolf' or 'Brian is green' or both.
invalid_hypothesis: It is improbable that 'Gertrude is a wolf' or 'Brian is green' 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
    0.0::factA.
    0.7::factB.
    0.9::factC.
    %hop1
    0.02::factX:-xor(factA,factB).
    0.1::factY:-or(factA,factC).
    0.0::factZ:-and(factB,factA).
  
    %hop2
    conclusion:-or(factC,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Gertrude is a wolf' or 'Brian is green' or both.