context: There is almost no chance that Jessica is a wolf. It is impossible that Lily is a rhino. It is likely that John went to the office. It is almost certain that if 'Jessica is a wolf and John went to the office' then Brian is white. It is likely that if either 'John went to the office' or 'Jessica is a wolf' but not both then Emily is a cat. It is highly unlikely that if 'Jessica is a wolf and Lily is a rhino' then Greg is a swan.
hypothesis: It is certain that 'Greg is a swan and Jessica is a wolf'.
valid_hypothesis: It is impossible that 'Greg is a swan and Jessica is a wolf'.
invalid_hypothesis: It is certain that 'Greg is a swan and Jessica is a wolf'.
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
    0.02::factA.
    0.0::factB.
    0.7::factC.
    %hop1
    0.95::factX:-and(factA,factC).
    0.7::factY:-xor(factC,factA).
    0.05::factZ:-and(factA,factB).
  
    %hop2
    conclusion:-and(factZ,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Greg is a swan and Jessica is a wolf'.