context: There is little chance that Bernhard is yellow. It is probable that Greg is a swan. It is unlikely that Mary went to the garden. There is almost no chance that if 'Greg is a swan and Mary went to the garden' then Jeff moved to the office. It is unlikely that if 'Greg is a swan' or 'Mary went to the garden' or both then Julius is green. It is probable that if 'Mary went to the garden' or 'Greg is a swan' or both then Lily is a frog.
hypothesis: It is probable that 'Greg is a swan and Jeff moved to the office'.
valid_hypothesis: It is impossible that 'Greg is a swan and Jeff moved to the office'.
invalid_hypothesis: It is probable that 'Greg is a swan and Jeff moved to the office'.
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.
    0.7::factB.
    0.2::factC.
    %hop1
    0.02::factX:-and(factB,factC).
    0.2::factY:-or(factB,factC).
    0.7::factZ:-or(factC,factB).
  
    %hop2
    conclusion:-and(factB,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'Greg is a swan and Jeff moved to the office'.