It is certain that Mary took the milk. There is a very good chance that Greg is a rhino. It is almost certain that Brian is white. It is probable that if either 'Brian is white' or 'Mary took the milk' but not both then Lily is yellow. It is impossible that if 'Mary took the milk and Brian is white' then Bernhard is yellow. It is unlikely that if 'Mary took the milk' or 'Greg is a rhino' or both then Jason is tired.
It is highly unlikely that 'Mary took the milk and Lily is yellow'.
It is highly unlikely that 'Mary took the milk and Lily is yellow'.
We believe that 'Mary took the milk and Lily is yellow'.

  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
  1.0::factA.
  0.8::factB.
  0.95::factC.
  %hop1
  0.7::factX:-xor(factC,factA).
  0.0::factY:-and(factA,factC).
  0.2::factZ:-or(factA,factB).

  %hop2
  conclusion:-and(factA,factX).

  query(conclusion).
  
'Mary took the milk and Lily is yellow'.