It is highly unlikely that Brian is a swan. Chances are slight that Julius is yellow. It is probable that Mary went to the garden. It is almost certain that if 'Brian is a swan and Julius is yellow' then Bernhard is white. Chances are about even that if 'Brian is a swan and Mary went to the garden' then Jessica is a sheep. It is impossible that if either 'Julius is yellow' or 'Mary went to the garden' but not both then Bill left the milk.
It is probable that 'Brian is a swan and Mary went to the garden'.
It is highly unlikely that 'Brian is a swan and Mary went to the garden'.
It is probable that 'Brian is a swan and Mary went to the garden'.

  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
  0.05::factA.
  0.1::factB.
  0.7::factC.
  %hop1
  0.95::factX:-and(factA,factB).
  0.5::factY:-and(factA,factC).
  0.0::factZ:-xor(factB,factC).

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

  query(conclusion).
  
'Brian is a swan and Mary went to the garden'.