context: There is little chance that Julius is green. It is unlikely that John moved to the office. There is almost no chance that Brian is a frog. Chances are about even that if 'Brian is a frog and Julius is green' then Lily is a swan. It is probable that if either 'Julius is green' or 'Brian is a frog' but not both then Mary went to the kitchen. It is improbable that if either 'Julius is green' or 'John moved to the office' but not both then Sandra dropped the milk.
hypothesis: It is probable that 'Brian is a frog' or 'Julius is green' or both.
valid_hypothesis: There is little chance that 'Brian is a frog' or 'Julius is green' or both.
invalid_hypothesis: It is probable that 'Brian is a frog' or 'Julius 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
    0.1::factA.
    0.2::factB.
    0.02::factC.
    %hop1
    0.5::factX:-and(factC,factA).
    0.7::factY:-xor(factA,factC).
    0.1::factZ:-xor(factA,factB).
  
    %hop2
    conclusion:-or(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is a frog' or 'Julius is green' or both.