context: It is highly likely that Lily is a lion. Chances are slight that Jeff moved to the garden. It is almost certain that Bernhard is a swan. It is likely that if 'Lily is a lion and Jeff moved to the garden' then Julius is white. Chances are about even that if 'Lily is a lion' or 'Jeff moved to the garden' or both then Mary left the milk. It is almost certain that if 'Jeff moved to the garden and Bernhard is a swan' then John went to the office.
hypothesis: It is highly unlikely that 'John went to the office and Julius is white'.
valid_hypothesis: It is highly unlikely that 'John went to the office and Julius is white'.
invalid_hypothesis: It is probable that 'John went to the office and Julius is white'.
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
    0.9::factA.
    0.1::factB.
    0.95::factC.
    %hop1
    0.7::factX:-and(factA,factB).
    0.5::factY:-or(factA,factB).
    0.95::factZ:-and(factB,factC).
  
    %hop2
    conclusion:-and(factZ,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'John went to the office and Julius is white'.