context: Chances are slight that Winona is a mouse. It is highly likely that Lily is a lion. It is highly likely that Julius is yellow. There is a very good chance that if either 'Lily is a lion' or 'Julius is yellow' but not both then Mary went to the office. It is likely that if 'Winona is a mouse and Julius is yellow' then John took the football. It is impossible that if 'Lily is a lion' or 'Winona is a mouse' or both then Greg is white.
hypothesis: We believe that 'Mary went to the office and Winona is a mouse'.
valid_hypothesis: There is almost no chance that 'Mary went to the office and Winona is a mouse'.
invalid_hypothesis: We believe that 'Mary went to the office and Winona is a mouse'.
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.
    0.9::factB.
    0.9::factC.
    %hop1
    0.8::factX:-xor(factB,factC).
    0.7::factY:-and(factA,factC).
    0.0::factZ:-or(factB,factA).
  
    %hop2
    conclusion:-and(factX,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary went to the office and Winona is a mouse'.