It is almost certain that Brian is a swan. It is probable that Bill went to the kitchen. It is impossible that Greg is a rhino. It is impossible that if 'Brian is a swan and Bill went to the kitchen' then Lily is green. There is a better than even chance that if either 'Brian is a swan' or 'Greg is a rhino' but not both then Bernhard is white. It is certain that if 'Brian is a swan' or 'Greg is a rhino' or both then Emily is a mouse.
It is improbable that 'Bernhard is white and Emily is a mouse'.
There is a better than even chance that 'Bernhard is white and Emily is a mouse'.
It is improbable that 'Bernhard is white and Emily is a mouse'.

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

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

  query(conclusion).
  
'Bernhard is white and Emily is a mouse'.