It is likely that Lily is a swan. It is likely that Winona is a cat. It is certain that Brian is white. We believe that if either 'Winona is a cat' or 'Brian is white' but not both then Yann is tired. There is a better than even chance that if 'Brian is white and Lily is a swan' then Bernhard is a rhino. It is almost certain that if either 'Lily is a swan' or 'Brian is white' but not both then Mary moved to the garden.
It is almost certain that 'Lily is a swan and Bernhard is a rhino'.
Chances are about even that 'Lily is a swan and Bernhard is a rhino'.
It is almost certain that 'Lily is a swan and Bernhard is a rhino'.

  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
  0.7::factA.
  0.7::factB.
  1.0::factC.
  %hop1
  0.75::factX:-xor(factB,factC).
  0.6::factY:-and(factC,factA).
  0.95::factZ:-xor(factA,factC).

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

  query(conclusion).
  
'Lily is a swan and Bernhard is a rhino'.