context: There is little chance that Lily is a rhino. There is a better than even chance that Brian is a frog. It is certain that Mary dropped the milk. There is a better than even chance that if 'Mary dropped the milk and Lily is a rhino' then Julius is white. It is likely that if 'Brian is a frog' or 'Mary dropped the milk' or both then Bernhard is white. Chances are about even that if either 'Lily is a rhino' or 'Mary dropped the milk' but not both then John moved to the office.
hypothesis: It is probably not the case that 'Brian is a frog and John moved to the office'.
valid_hypothesis: It is probably not the case that 'Brian is a frog and John moved to the office'.
invalid_hypothesis: We believe that 'Brian is a frog and John 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.
    0.6::factB.
    1.0::factC.
    %hop1
    0.6::factX:-and(factC,factA).
    0.7::factY:-or(factB,factC).
    0.5::factZ:-xor(factA,factC).
  
    %hop2
    conclusion:-and(factB,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is a frog and John moved to the office'.